JP4823183B2 - Copper-based sintered sliding material and sintered sliding member using the same - Google Patents

Description

  The present invention relates to a copper-based sliding material aiming at improving seizure resistance and / or wear resistance of a bearing under high surface pressure, preventing occurrence of abnormal noise, and extending a greasing interval, and a sintered slide using the same. The present invention relates to a moving member.

  Conventionally, as a bearing material used under higher surface pressure and low speed conditions such as construction machine work equipment bushes, carburized or induction hardened steel bushes with an emphasis on wear resistance are used under grease lubrication. It has been. In particular, since this type of work machine has severe lubrication conditions under high surface pressure, a lubrication film treatment is applied to the sliding surface of the steel bush to prevent unpleasant noise during work. In order to improve the lubricity of grease, a large number of grease grooves are formed.

  Also, from the viewpoint of easy maintenance by extending the greasing interval of the grease, for example, Fe-C-Cu is used as a basic type, and lubricating oil is impregnated in the pores of the iron-based sintered sliding material of a hard martensite base Oil-impregnated sintered bearings, oil-impregnated sintered bearings in which harder tool powders and ceramic powders are added to this iron-based sintered sliding material, etc. are also partly used in light load working machine parts ( Non-patent document 1).

  In addition, bronze bearings such as Cu-Sn-Pb and Cu-Sn-Pb-C are also encouraged for copper-based sintered bearing materials.

  In order to extend the greasing interval to the bearing part of a working machine etc., a high-strength brass bush is provided with a machined hole with an area of about 30% of the sliding part area, and the hole is overlapped in the sliding direction. The bearing material (for example, made by Oiles Kogyo Co., Ltd., 500SP) in which the solid lubricant (porous) graphite is embedded in the hole, and the metal sintered body added with a large amount of the solid lubricant (for example, Toshiba Tungaloy Co., Ltd.) In some cases, SL alloy) is used.

  The multilayer sintered sliding member used under high surface pressure conditions includes a steel back metal, 10 to 30 parts by weight of copper, graphite, and 0. Patent Document 1 discloses a sliding bearing including an iron-based sintered alloy layer of 1 to 6.5 parts by weight, molybdenum disulfide 0.1 to 7 parts by weight, and the balance being iron.

  Further, as a copper-based multilayer sintered sliding material used under high surface pressure conditions, 5 to 13 wt% Al in which graphite as a solid lubricating component is dispersed and contained in a range of 3 to 8 wt%, A multilayer sintered sliding material obtained by integrally bonding an aluminum bronze sintered sliding alloy having a composition range of 3 to 6 wt% Fe and 0.1 to 1.5 TiH to a steel plate through a bonding layer of a phosphorus alloy plate Patent Document 2 discloses a method for manufacturing the same.

  In the case of the above-mentioned working machine bushing that slides under a high surface pressure and at an extremely low speed, the conditions for forming the lubricating film become very strict. The steel bush does not suffer from high loads in terms of hardness, but it is an important problem that it is easy to seize or generate unpleasant noises, and shortens the greasing interval. Therefore, it is necessary to manage so that those problems do not occur.

  As the working machine bush, in the case of using the oil-impregnated iron-based sintered sliding material of the martensite base, there is no sag, and the seizure property is considerably improved as compared with the steel bush. When used at a very low speed and under a heavy load, such as a work machine, the out-of-lubrication condition easily occurs, so that it is not possible to sufficiently improve seizure resistance and prevent abnormal noise generation. There is a problem.

  Furthermore, in the case of improving the lubrication conditions during sliding by adding a large amount of lubricating oil to the voids in the sintered sliding material, the lubrication condition is reversed by the presence of many voids in the sintered body. There is a problem that it cannot be improved to the extent that anti-seizure resistance and abnormal noise are expected.

  Moreover, in order to improve the seizure resistance between the steel working machine pin and the working machine bush, a material using a bronze-based material such as Cu-Sn or Cu-Pb, which is a dissimilar material, will sag under high surface pressure. There is a problem and a problem that it wears very easily due to severe lubrication conditions.

  On the other hand, when the work machine bush is made of harder, high strength, high strength brass material, there is almost no sag, and there is a significant amount of noise compared to the steel bush. However, since the lubrication is easily lost as described above, there is a problem that the seizure resistance cannot be improved and the generation of abnormal noise cannot be sufficiently achieved.

  In addition, the above-mentioned bush is made by drilling a hard, high-strength, high-strength brass material, embedding high self-lubricating graphite in this hole, and further impregnating graphite with lubricating oil. Although the problem related to sag is solved, the area ratio of the holes for filling graphite is usually kept to 25-30%, so as the distance of sliding while swinging like a work machine becomes shorter As a result, there is a place where lubrication cannot be achieved, local seizure occurs, and sufficient self-lubricity cannot be obtained for a long time. Also, drilling for graphite embedding and graphite filling, etc. This process has a problem that the cost is remarkably increased.

  Moreover, in the case of using an oil-impregnated iron-based sintered sliding material based on martensite as an inexpensive work machine bush, there is no sag and it is considerably improved in terms of seizure resistance compared to the steel bush. However, there is a problem that it is not enough.

  On the other hand, in the one disclosed in Patent Document 1, it is considered that seizure resistance is improved because a large amount of solid lubricant is dispersed. However, a large amount of solid lubricant is dispersed and / or described later. Because of its manufacturing method, the iron-based sintered sliding material has extremely poor toughness, lack of strength, and its wear resistance becomes a problem. For example, it easily breaks during rock drilling. .

In addition, the manufacturing method disclosed in Patent Document 1 includes a steel back metal in a press mold and an iron-based sintered material mixed powder on the inner peripheral surface thereof, and the mixed powder is mixed with 50 to 300 kgf. This is a method of pressing and molding at a pressure of / cm ² and then taking out from the mold and sintering. According to such a method, the sintered density is extremely low, and the iron-based sintered body at the time of sintering is used. Are greatly shrunk, resulting in extremely unstable sintered joining, and the strength of the sintered body is not sufficient.

  Further, as in the technique disclosed in Patent Document 2, in order to enhance seizure resistance, a large amount of solid lubricant graphite, which is 3 to 8% by weight (about 12 to 36% by volume), is added to high-strength aluminum. Even those contained in the bronze sintered material do not show sufficient seizure resistance because the Cu-Al sintered alloy has a soft α-phase structure, and contains a large amount of graphite that supplements the seizure resistance. Due to the weakness of the strength, there is a problem that the sliding characteristics under sufficiently high surface pressure are not ensured and the wear resistance is not sufficient.

  In addition, in this prior art, since a solid lubricant is contained in a large amount and a liquid phase generating component such as Sn is not contained, the sinterability becomes difficult with a metal sintered body, so as to obtain a practical strength. Requires pressure treatment during sintering. For example, a phosphor bronze plate comprising an Al bronze-based sintered sliding material containing 3 to 8 wt% graphite, 8 to 10 wt% Al, 4 to 6 wt% Fe, and 0.2 to 1.0 wt% Ti as appropriate amounts. The multi-layer sintered sliding member integrated with the back metal via the bonding layer requires a pressure treatment at the time of sintering, and there is a problem that high cost in at least the integration step is unavoidable.

"Sintered machine parts-design and manufacture", edited by Japan Powder Metallurgy Association, Technical Shoin, published in 1987, P339 JP-A-11-117940 JP-A-5-156388

  The present invention has been made in view of such problems, and improves the seizure resistance and / or wear resistance of the bearing under high surface pressure, prevents the generation of abnormal noise, and extends the greasing interval. It is an object of the present invention to provide a copper-based sintered sliding material aiming at the above-mentioned purpose and a sintered sliding member in which the copper-based sintered sliding material is integrated with a back metal.

  More detailed objectives are: (1) A remarkable improvement in adhesion resistance is achieved by the Fe alloy phase and Cu alloy phase containing Al, and (2) Abrasion resistance is improved by martensite organization of the Fe alloy phase. (3) Heat generated during sliding is absorbed by secondary transformation of the Fe alloy phase (regular-irregular transformation and magnetic transformation) to delay the temperature rise on the lubrication surface. (4) Hard and seizure resistance The Cu—Al-based β phase, which is excellent in the above, becomes a Cu alloy phase dispersed as a liquid phase in the copper-based sintered sliding material and / or a Cu alloy phase finely precipitated and dispersed in the iron alloy phase, (5 ) Providing a copper-based sintered sliding material that prevents sticking and slipping abnormal noise that occurs at low speed boundary lubrication due to the oil content in the pores and the dispersion of the solid lubricant. (6) Contains Al that significantly expands the iron-based sintered body and Cu that contracts. To provide a cylindrical or multilayered sintered sliding member is joined to the inner diameter surface of the substantially cylindrical iron-based material.

  Furthermore, it is providing the copper-type sintered sliding material and sintered sliding member which disperse | distribute the Fe alloy phase excellent in seizure resistance and abrasion resistance in Cu-type sintered material at high concentration.

  Work equipment bearing materials used at low speed and under sliding conditions that are prone to loss of lubrication under high surface pressures have moderate hardness and excellent seizure resistance and / or wear resistance. As a result, it is possible to prevent the generation of abnormal noise and extend the greasing interval. From this point of view, in the present invention, as a material having such characteristics, Fe-Al-Cu-based, Fe-Al-Cu-C containing Al in the Fe phase, which easily forms an Fe-based alloy ordered phase. This is characterized by the fact that the alloy phase is excellent. In particular, the Fe-Al-Cu-C-based alloy phase containing carbon can be easily hardened and hardened into a martensite and / or bainite structure in the cooling stage after sintering, thereby improving its wear resistance. Can be handled at low cost.

  Referring to the phase diagram of HANSEN, examples of systems that exhibit a regular phase in a practical bearing Fe-based alloy include Fe—Al, Fe—Si, Fe—Co, and Fe—Ni. From the above, those using mainly Fe—Al and Fe—Si are very effective.

  In addition, both Al and Si form an oxide layer on the surface of the iron-based sliding material, and have the effect of being excellent in corrosion resistance and oxidation resistance. It is also advantageous to significantly improve its seizure resistance by preventing contact.

Note that there are Fe ₃ Al, FeAl, Fe ₃ Si, and FeSi as the Fe—Al and Fe—Si ordered phases. These crystals all have a BCC structure, and since the Fe atoms and Al atoms and / or Si atoms are attracted very strongly, the atoms are regularly arranged at the closest distance, so that the hardness of this ordered phase. Is well known to show a hardness close to that of an intermetallic compound as the degree of order increases. In addition, since Fe-Al alloys to which Ni and Co are added also involve a two-phase separation reaction into two kinds of ordered phases of Fe-Al and Ni-Al or Co-Al, for example, an aging treatment at 600 ° C. Or by slowing down the cooling rate after sintering, it can be remarkably cured and is extremely effective for imparting wear resistance. However, these regular phase hardness does not exceed Vickers hardness Hv800, and when used as a sliding material, the working machine pin surface that is the above-mentioned mating sliding material is cured by heat treatment, It is preferable that there is no attack by the bush and that the sliding material itself is excellent in wear resistance.

  As can be inferred from the fact that the ordered phase has a hardness close to that of an intermetallic compound, it is extremely stable when Fe atoms and Al atoms and / or Si atoms are regularly arranged. Conversely, if the atomic arrangement is disturbed by adhesion, it becomes extremely unstable. Therefore, it is clear from the chemical point of view that reducing the adhesion of the steel working machine pin is preferable for the characteristics as the sliding material.

  Furthermore, since a significant endothermic reaction is accompanied at the stage where the regular atomic arrangement becomes irregular, it is more preferable that the sliding material according to the present invention exhibits an action of suppressing heat generation on the sliding surface. In addition, even when the sliding surface is heated by frictional heat, it has an endothermic effect in a wide temperature range that is a secondary transformation from the regular phase to the irregular phase, even if the sliding surface is heated by frictional heat. It is clear that it is preferable to improve the adhesion resistance as a result by utilizing.

  Furthermore, the endothermic reaction similar to these regular / disorder transformations is also caused by a magnetic transformation that undergoes a secondary transformation from a ferromagnetic material to a paramagnetic material. For example, the regular / disorder transformation temperature and the magnetic transformation temperature It is possible to design so as to cause an extremely remarkable endothermic action in a wide temperature range that is further secondary transformation by adjusting the, and it is also possible to improve the adhesion resistance. It is the characteristic of the sliding material which concerns on.

In the Fe-Al system, referring to the phase diagram of HANSEN, if the composition range in which the Fe ₃ Al ordered phase is expressed is estimated, the sliding surface of a general iron-based material starts to seize at 100 ° C. For example, it is appropriate to contain at least 2 to 20% by mass of Al in the Fe-based alloy phase. Similarly, even in the case of Fe—Si, an addition amount within the same range is appropriate. Further, it is also preferable to use Si and Al in an appropriate mixture. However, the Fe-based alloy phase in the iron-based sintered sliding material at that time contains 1 to 10% by mass of Si, and 21% by mass of Al + Si. It is clear that it is appropriate to contain the content of no more than%.

  In the Fe alloy phase, it is preferable to contain 5 to 40% by mass of one or more of Co and Ni, and to adjust the hardness of the Fe alloy phase to Hv 300 to 800.

  In addition, when producing an iron-based sintered sliding material containing Al in a high concentration according to the present invention, when an elementary powder of metal Al is added, it exhibits extremely remarkable expansibility, Fe-Al, Fe -The Al-C system has a problem that it cannot be used as a sliding material from a very strong viewpoint. Therefore, in the present invention, (1) one or more of phosphorus (iron), Si, and Ti is added in an amount of 0.25% by mass or more to enhance the reducibility and at the same time to make a partial liquid phase appear, thereby increasing the sinterability. (2) Add 10% by mass or more of Cu powder and promote the sintering by generating a Cu-based liquid phase in the early stage of sintering. (3) Solve the melting point by dissolving in Cu powder. The above-mentioned remarkable expansibility is controlled by means of promoting the sinterability by adjusting elements such as Sn, Si, phosphorus, Mn, etc. to be lowered within a range of 10% by mass, and mainly comprising Fe-Al system. The ordered-sintered sliding material and ordered phase can be easily manufactured with Cu-based components.

  In particular, in order to solve the difficult sinterability by using a mixed powder of soft Fe powder and Al powder and to manufacture a cheaper bearing, the amount of added Cu is reduced as much as possible, Sn, Ti, P, It is preferable to improve the sinterability by adding one or more of Si within the range of 0.1 to 5% by mass.

  Addition of 10 to 50% by mass of Cu increases the sinterability of the material by sintering at a relatively low temperature side, but addition of 50% by mass or more increases the amount of liquid phase during sintering, The shape retention of the sintered body is deteriorated and the cost is increased.

  In addition, when carbon is added, the solid phase of Cu in the iron alloy phase decreases, so the amount of liquid phase increases when the amount of liquid phase during sintering is compared between the same amount of added Cu. The addition of C can reduce the addition of Cu, which is also good for reducing the cost.

  The above-described expansion due to the addition of Al increases as the amount of Al added increases, so when there is a problem that the amount of Cu added to suppress it increases, the amount of addition of metal Al powder is suppressed, and Fe-Al It is extremely effective to use alloy powder. Alternatively, utilization of Fe—Al alloy powder, Cu—Al alloy powder, or the like may be preferable as an Al alloy addition method.

  Furthermore, when manufacturing the iron-based sintered sliding material, it is difficult to form and sinter by mixing and sintering Fe-based alloy powder and Cu powder close to the Fe alloy phase composition in the sliding material. In order to avoid this, and to suppress the expansibility during remarkable sintering, it is preferable, but the problem is that the availability of the Fe-based alloy powder and the powder cost are high.

  The appropriate amount of C added in the Fe—Al—Cu—C sintered sliding material is 0.05 mass% or more depending on the Fe alloy phase hardness (Hv = 250 to 850) obtained by cooling after sintering. The upper limit is preferably 1.5% by mass from the viewpoint of improving the wear resistance by dispersing cementite particles in the Fe alloy phase. Here, the Fe alloy phase may be composed of one or more structures of martensite, bainite, and granular cementite.

  In addition, Si, Mn, Ni for improving the quenching hardenability and / or age hardenability of the Fe alloy phase so that the Fe alloy phase of the iron-based sintered sliding material has a martensite and / or bainite structure by the cooling. It is preferable that one or more alloy elements of Cr, Mo, V, P, Ti, W and Co are contained in an amount of 0.1 to 5% by mass. In particular, the addition of Ni shows remarkable age-hardening properties with the contained Al, Si, and Ti, so it is preferable from the viewpoint of wear resistance, but is limited to 5% by mass or less from the viewpoint of cost. The same effect as Ni can be observed by adding Co. The upper limit of the amount of Co added is preferably 5% by mass for the same reason.

  As described above, the function of quenching and hardening the iron-based sintered sliding material by adding C may be realized by subjecting the iron-based sintered sliding material not containing C to carburizing and hardening. It is clear that it is good. In particular, the present iron-based sintered sliding material containing Al is effectively hardened by nitriding and gas soft nitriding, and thus is effective in improving the wear resistance.

Furthermore, as described above, mixing and sintering Fe-Al alloy powder and Cu powder close to the Fe alloy phase composition of the iron-based sintered sliding material suppresses significant expansion during sintering. Although it is a preferable means in the above, 2000 kgf / cm ^{2 of} mixed powder for Fe—C or Fe—C—Cu based sintered material excluding Al, or mixed powder in which the amount of Al added to the mixed powder is minimized. At the same time as sintering the press-molded body pressurized as described above, the Cu-Al-based material is melted and infiltrated into the molded body, or after the press-molded body is once sintered, the Cu-Al-based material is re-sintered. It is preferable to manufacture Fe-Al-Cu-based and Fe-Al-Cu-C-based sintered sliding materials by infiltrating.

  In each of the above-mentioned inventions, the Cu alloy phase of the original liquid phase dispersed in the grain boundary of the iron-based sintered sliding material and / or the fine Cu alloy phase precipitated in the Fe alloy phase of the iron-based sintered sliding material Preferably contains the β phase and / or its transformation phase described in the Cu—Al phase diagram.

  In the present invention, an element such as Sn, Si, phosphorus, Mn, etc., which lowers the melting point by solid solution in Cu-Al, is adjusted within a range of 10% by mass or less with respect to Cu to lower the infiltration temperature. By controlling the expansibility, an iron-based sintered sliding material mainly composed of Fe-Al-Cu-C system can be easily manufactured.

  Sn and Al have repulsive properties, and Sn is easily discharged from the sintered body during sintering or cooling after infiltration (easy to sweat). Therefore, in the present invention, Sn is added to the amount of Cu added. The perspiration was prevented by adding in the range of 10% by mass or less. Ti also reacts with Al to strengthen the Cu alloy phase dispersed in the iron-based sintered sliding material of the present invention. Furthermore, Sn stabilizes the Cu-Al alloy-based β phase (see HANSEN phase diagram), so the addition of Ti serves to prevent the sweating of Sn and make the β phase appear more easily. The appearance of the β phase improves the seizure resistance during sliding (see JP 2001-271129 A). In addition, the fact that Sn can be present in the sintered body in a large amount is also preferable due to the bonding property with the back metal described later.

  In addition, as described later, the addition of Ti significantly improves the bondability with the iron-based material. The iron-based sintered sliding material of the present invention is applied to the inner surface of the cylindrical or substantially cylindrical iron-based material. This is extremely important for the production of a multi-layer iron-based sintered sliding member that is sintered or heat bonded.

  Furthermore, as described later, in the iron-based sintered sliding material of the present invention in which graphite is dispersed as a solid lubricant, there is a problem that the wettability of the Cu—Al, Cu—Sn alloy liquid phase and graphite is poor. The wettability can be remarkably improved by forming TiC on the graphite surface by adding Ti.

  As will be described later, as a result of EPMA composition analysis (X-ray microanalyzer analysis) of each phase in the Fe—Al—Cu sintered sliding material, Al and Ti are Fe ordered phases rather than Cu alloy phases. It is clear that Sn is concentrated in the Cu-based phase while P is solid-solved almost uniformly, whereas it is concentrated inside. Further, it has been clarified that the Cu concentration dissolved in the Fe alloy phase is about 25% by mass, and the Fe concentration dissolved in the Cu alloy phase is about 5% by mass.

  Therefore, the Fe-Al-Cu and Fe-Al-Cu-C-based sintered sliding materials containing 10 mass% or more of Cu have a maximum of about 25 mass% Cu in the Fe alloy phase during sintering. Since it is in solid solution, it is expected that a fine Cu alloy phase will precipitate inside the Fe alloy phase by cooling from the sintering temperature or by aging treatment at a low temperature. In particular, when the precipitated Cu alloy phase is excellent in the above-mentioned seizure resistance (see Japanese Patent Application Laid-Open No. 2001-271129) and has a high hardness β phase, it contributes to an improvement in seizure resistance of the Fe alloy phase itself. It is clear.

  Further, it can be easily understood that Sn increases the sliding characteristics of the Cu alloy phase by concentrating in the Cu-based phase while hardly dissolving in the Fe ordered phase. As disclosed in the official gazette, this Sn significantly stabilizes the Cu-Al-based β phase to make the β phase appear easily, and at the same time lowers the melting point of the Cu alloy phase to increase the sinterability. However, when a large amount of Sn is added in the presence of Al, a large amount of intermetallic compounds are precipitated and become markedly embrittled. Therefore, the amount of Sn added is set to 10% by mass or less of the amount of Cu added. .

  Further, it is obvious that one or more elements of Sn, Ti, Ni, Mn, Si, and P, which enhance the sliding characteristics of the β-phase Cu alloy phase, are desirable.

  The distribution and size of the Cu alloy phase in the iron-based sintered sliding material, the dispersibility of pores and the dispersibility of the solid lubricant described later are closely related to the sliding characteristics and strength of the sliding material. Is well known, and the iron-based powder used for the iron-based sintered sliding material is preferably 60 μm (250 mesh or less), more preferably 45 μm (325 mesh or less).

    As described above, since it is clear that the excellent sliding characteristics and wear resistance of the iron-based sintered sliding material are in the Fe alloy phase in the sliding material, in the present invention, We developed a copper-based sintered sliding material in which particles in the Fe alloy phase component range are dispersed in a Cu-based alloy matrix.

In short, the sintered sliding material according to the present invention is:
A copper-based sintered sliding material comprising a sintered structure in which a Cu-Al-based alloy phase is used as a grain boundary phase to connect an Fe ordered phase,
The Cu—Al-based alloy phase includes Al: 6.25 to 9.85% by mass, Sn: 3.71 to 16.79% by mass , Ti: 0.08 to 1.52% by mass, and Fe: 2.36 to 5.45 mass%, P: 0.05 to 0.13 mass%, Cu: 69.92 to 83.86 mass%, and β described in the Cu-Al phase diagram Comprising a phase and / or its transformation phase,
The Fe ordered phase, Al: the 12.32 to 16.42 mass%, Cu: and 14.33 to 22.74 wt%, P: and 0.07 to 0.13 wt%, Sn: 0.26 and 0.7 mass%, Ti: and 0.18 to 1.01 wt%, Fe: is characterized in that consisting of 59.18 to 72.36 wt% (first invention).

Further, Fe alloy phase dispersed in the copper-based sintered sliding material is martensite, bainite, Ri Contact consist of one or more tissues of the granular cementite, copper-based sintering hardness is Hv = 250-850 A sliding material is preferred.

  Furthermore, in order to uniformly supply the lubricating oil to the bearing sliding surface, dispersing the pores containing the lubricating oil in the iron-based sintered sliding material not only improves the seizure resistance of the bearing, Since there is an effect of remarkably extending the greasing interval to the bearing, in the present invention, the pores in the above-described iron-based sintered sliding material for bearing are defined.

  Usually, the iron-based sintered sliding material and / or the copper-based sintered sliding material contains 0.5 to 30% by volume of pores, but as the sliding material, 3 volumes in which the pores are ventilation holes. % Or more is desirable, and the upper limit is desirably not to exceed 30% by volume from the viewpoint of the strength of the sintered body.

  Further, the viscosity of the lubricating oil impregnated in the pores can be variously changed depending on the use conditions (for example, ISO viscosity grade 100 to 1500), but it is used with high surface pressure and low sliding characteristics such as a work machine bush. In such a case, it is preferable to impregnate with a higher viscosity lubricating oil, and a synthetic lubricating oil having a high heat resistance or a material obtained by melting it with 2 to 10% by weight of wax may be impregnated.

  In addition, in the case of containing a large amount of pores, it is also effective to impregnate a resin such as PA (polyamide) having excellent lubricity or a wax.

Further, in the iron-based sintered sliding material, graphite, MoS ₂ , WS ₂ , MnS, and CaF, which are well known in the past and have high solid lubricity, in order to improve seizure resistance and wear resistance. _It is preferable to add ₂ solid lubricants (3-9 mass%) .

  When graphite, which is a solid lubricant, is dispersed in an iron-based sintered sliding material, the above-mentioned fine iron of 45 μm or less with respect to graphite mainly having a particle size of 0.06 to 1 mm. It is preferable to surround the graphite particles using a system powder. Moreover, it is preferable that the graphite used as the solid lubricant is adjusted to be granular by means such as granulation.

  In addition, if there are many irregular pores around the graphite particles, the strength is significantly reduced due to the notch action at that position. Therefore, an infiltration method as described later is used to reduce the porosity of the iron-based firing. From the viewpoint of strength, the porosity of the iron-based sintered sliding material when containing a larger amount of graphite is preferably as small as possible, for example, 0.1 to 10% by volume. preferable.

In addition, graphite dissolves in the iron-based matrix, and large carbides such as cementite are formed around the graphite. In many cases, the mating material is strongly worn during sliding. Also in MoS ₂ and WS ₂ In order to prevent the reaction with iron on the surface of the solid lubricant when the graphite, MoS ₂ , WS ₂ or the like is dispersed and sintered as the solid lubricant, it reacts to form iron sulfide or copper sulfide. It is desirable that the glass-based material is coated (see JP-A-4-254556).

Further, as means for improving the seizure resistance and wear resistance by the hard dispersion particles, Mo (0.2 to 10% by mass), W metal particles, oxides, carbides, nitride ceramics, carbide (Co- WC-based), cermet (Ni-TiC-based), carbide of high-speed steel powder, hard dispersion containing nitride, and one or more intermetallic compounds of FeCo, NiAl, TiAl, NiSi, NiTi are included. It is preferable .

Further, it is preferable that at least 2 to 9% by mass of the granulated graphite is dispersed, and further 0.1 to 5% by mass of MoS ₂ , WS ₂ , and MnS is dispersed .

  Next, for the purpose of reinforcing the low-strength iron-based sintered sliding material of the present invention containing a large amount of solid lubricant, the purpose of reducing the amount of the iron-based sintered sliding material of the present invention, In the present invention, it is preferable that the above-described iron-based sintered sliding material is integrated with a back metal and used as a multilayer sintered sliding member. Here, as an integration method, there are various methods of brazing and adhering the sliding material, and a method by a sintered joining method for joining when the sliding material is sintered.

  In particular, as a method of sintering and bonding the above-described copper-based sintered sliding material to the back metal, there is a conventional method of sintering and bonding the Cu-Sn, Cu-Sn-Pb-based sintered sliding material to the back metal plate. Easy to apply. In this method, the Fe alloy phase component powder is mixed with a bronze-based Cu—Sn, Cu—Sn—Pb based powder, a metal Cu, Sn, Pb powder, or a powder prepared with an alloy powder thereof. After spraying the mixed powder on the steel plate as the backing metal and temporarily sintering and joining at a temperature of 700 ° C. or higher, the temporary sintered body is pressure-molded and sintered again by mechanical means such as a rolling mill. This is a manufacturing method, and in order to obtain a higher-density sintered layer, pressure molding and sintering are repeated.

In the case of obtaining a cylindrical sintered sliding member, it is preferable to form and process an iron-based sintered sliding material into a cylindrical shape or a plate shape and to integrate it into a back metal made of an iron-based material ( second invention). ).

In the second invention, the hardenability of the iron-based material used as the back metal is a DI value of 2.0 or less, and shows a structure of ferrite, pearlite, or bainite even by gas quenching or oil quenching. by martensite some more Fe alloy phase of an iron-based sintered sliding material, which forms an bonding, preferably to compressive residual stress in the iron-based sintered sliding material acts (3 invention). In this case, the porosity of the iron-based material serving as the backing metal is preferably adjusted to 3 to 20% by volume, and each pore is preferably impregnated with a lubricating oil ( fourth invention).

Moreover, in the multilayer sintered sliding member formed into a cylindrical shape to be a multilayer sintered bush, it is preferable that the chamfering of the outer peripheral surface of both end surface portions is smaller than the chamfering of the inner peripheral surface .

Furthermore, in the second invention to the fourth invention, a multilayered sintered sliding member formed in a cylindrical shape, and a collar portion is provided on the back metal so as to slide under a thrust load. It is preferable that an abrasion- resistant material and / or a sliding material is disposed on the buttocks sliding surface ( fifth invention). Here, the wear-resistant material or the sliding material is one of carbide, stellite, iron-based wear-resistant material, ceramics, and Cu-based wear-resistant material, and these are sprayed, brazed, sintered bonded, welded, It is good to integrate by any means of immersion joining and adhesion | attachment ( 6th invention).

Furthermore, it is preferable that the iron-based sintered sliding material in each of the above inventions is integrated on the flange sliding surface ( seventh invention).

Next, in order to produce a multilayer sintered sliding member formed into a cylindrical shape or a substantially cylindrical shape,
The iron-based sintered material formed or sintered body whose components are adjusted in advance is arranged so as to be substantially inscribed in the inner surface of the back metal made of a cylindrical or substantially cylindrical iron-based material. The backing metal while expanding the iron-based sintered material by infiltrating the copper-based or copper aluminum-based material whose component is adjusted to a lower melting point into the iron-based sintered material molded body or sintered body while heating. It is preferable to use a method of joining to the substrate.

  In addition, in order to quench and harden the Fe alloy phase in the copper-based sintered sliding material, it is necessary to cool at least from 850 ° C. or higher, so that the sintering temperature is 850 ° C. or higher and sintering It is preferable that alloy elements such as Ni, Cr, Mn, and Mo are adjusted so that they are quenched and hardened at a later cooling rate. However, the back metal plate is preferably made of, for example, SPCC or carbon steel plate so as not to be hardened by hardening at the cooling rate.

  Moreover, in order to make the above-mentioned iron-based sintered sliding material into a multilayer sintered sliding member by the same method, it is preferable to increase the amount of Fe alloy phase powder added. Will not change.

In the method of manufacturing the multilayer iron-based sintered sliding member, the inner diameter surface of the cylindrical or substantially cylindrical iron-based material has an outer diameter that is substantially the same as or slightly smaller than the inner diameter, and excludes Al. Arranged compacts that are pressure-molded at 2000 kgf / cm ² or more of mixed powders for Fe-C and Fe-C-Cu-based sintered materials, or mixed powders with minimal addition of Al to the mixed powders At the same time as this molded body is sintered, the Cu-Al material is melted and infiltrated into the molded body, so that expansion starts by sintering and diffusion of the Al component in the molded body. Bonding and sliding materials can be joined while being pressed against the inner surface of the iron-based material.

  It should be noted that the infiltrated Fe-C or Fe-C-Cu press-molded body may be a method of infiltrating by placing it on the inner surface of the iron-based material after sintering once. It is.

  Furthermore, even in the iron-based sliding material made by the infiltration method, it is easily assumed that further re-expansion appears by further progress of Al alloying by reheating after infiltration. It is better to use a method in which an iron-based sintered sliding material made by the infiltration method is placed on the inner surface of the iron-based material and reheated to join, and an appropriate brazing agent is placed on the joint surface in advance. It is also preferable to improve the bonding property.

  The manufacturing principle of the multilayer sintered sliding member formed by sintering and joining the iron-based sintered sliding material to the inner diameter part of the cylindrical and / or cylindrical iron-based back metal material is the iron-based The Al added at the time of sintering of the sintered sliding material starts to diffuse significantly on the low temperature side of 800 ° C. or higher, causing large expansion, and the expansion causes the iron-based sintered sliding material to have an inner diameter of the iron-based backing material. Sintering is performed while pressing against the surface, and the Cu alloy component that is the main component of the melting is melted at a temperature of 850 ° C. or higher while further raising the temperature, thereby improving the sinterability and increasing the strength.

  As a method for brazing the iron-based sintered sliding material formed into a cylindrical shape or a substantially cylindrical shape to the inner diameter surface of the cylindrical or substantially cylindrical iron-based material, a multi-layer firing formed into a cylindrical shape or a substantially cylindrical shape is performed. A sintered sliding member manufacturing method, in which an iron-based sintered sliding material is disposed so as to be substantially inscribed in an inner diameter surface of a back metal made of a cylindrical or substantially cylindrical iron-based material, and the sintered sliding material Preferably, a brazing agent is disposed between the moving material and the back metal, and brazing while pressing the sintered slide material against the back metal by high frequency heating from the inner peripheral surface of the sintered slide material. In order to quench and harden the Fe alloy phase in the iron-based sintered sliding material after the brazing, the brazing temperature is preferably 850 ° C. or higher.

  In order to quench and harden the iron-based sintered material, the amount of carbon is freely adjusted according to the required hardness, but is usually preferably in the range of 0.05 to 1.0% by mass. Furthermore, in the present invention, in the cooling process after sintering joining, one or more elements such as Ni, Mo, Cr, and W are hardenable so that one or more of martensite and / or bainite are formed and hardened. The iron-based material of the back metal is adjusted so that the iron-based material of the back metal is not hardened by hardening, and when the cooling is completed, the iron-based sintered body expands by quenching transformation and the back metal is adjusted so that compressive stress remains. It is preferable to prevent the occurrence of peeling and cracking of the sintered layer.

  Further, when cracks are generated due to expansion and contraction in the axial direction of the cylindrical shape, it is preferable to sinter and join two or more shaped bodies of iron-based sintered material in multiple stages as a preventive means.

  It is obvious that steel, cast iron, sintered material, etc. can be applied as the cylindrical, substantially cylindrical or plate-shaped iron-based backing material. In the multilayer sintered sliding member in which the iron-based sintered sliding material is integrated, the iron-based sintered material is used in order to contain more lubricating oil and achieve a longer greasing interval. It is preferable to use a backing metal and to contain a large amount of lubricating oil in the backing metal.

In order to manufacture the multilayer sintered sliding member, the iron-based sintered body to which Al, which is a metal that expands the iron-based sintered material, is added contains at least 0.1% by mass of Al. As a result, the expansibility is remarkably confirmed, so that at least 0.1% by mass of Al, which is a metal that expands the iron-based sintered material, is contained, and a liquid phase is generated on the high temperature side to thereby obtain a sintered body strength. In order to ensure sintered bondability, it contains at least one of 10 to 50% by weight of Cu, 0.1 to 10% by weight of Sn and 0.1 to 10% by weight of Ti. A cylindrical molded body made of an iron-based sintered material having an outer diameter that is substantially the same as or slightly smaller than the inner diameter of a back metal made of a cylindrical or substantially cylindrical iron-based material is inserted and arranged on the inner diameter surface of the back metal And
(A) By heating at a temperature of 700 ° C. or higher for a predetermined time, the sintered material is expanded and sintered and joined to the back metal;
(B) It is preferable that the sintered material be densified by generating a Cu-based alloy liquid phase by further heating and heating at a temperature of 820 ° C. or higher.

  The expansibility due to the addition of Al begins to appear remarkably in the temperature range of 800 ° C. or higher where the diffusibility of the alloy becomes active. If Cu does not coexist, it continues to expand even at 1100 ° C. It can be seen that when added above, shrinkage begins with the generation of a liquid phase at around 1050 ° C.

  Further, by adding carbon, the solid solubility of Cu in the Fe alloy phase is reduced, the amount of Cu liquid phase during sintering is increased, and the sinterability is further promoted.

  In the present invention, by using the expansion and contraction characteristics of Fe—Al—Cu, a third alloy element that does not contribute much to the contractility is added in a temperature range of 800 ° C. or more and 1050 ° C. or less that exhibits maximum expansion. Bondability was ensured by generating a liquid phase, and the iron-based sintered body was densified and the sintered body strength was ensured by heating at a temperature of 1050 ° C. or higher. In the Fe-Al-Cu-based sintered sliding material, the third element for improving the sintering bondability with the cylindrical or substantially cylindrical iron-based material is at least Sn, P, Ti, One or more types of Si are selected. For example, when Sn or Ti is added, a large expansibility is exhibited, but it has a characteristic that the melting point is lowered by alloying with Cu. The amount of each additive is adjusted in the range of 1 to 10% by mass, but is preferably 5% by mass or less from the viewpoint of action and cost.

  In particular, even if a small amount of Ti is added, a carbide is formed at the interface between the iron phase containing carbon and the Cu phase, and the wettability with the Cu liquid phase is remarkably improved. Is effective.

  It is well known that P imparts expansibility when added to an iron-based sintered body containing carbon as phosphorous iron. Further, alloying with Cu shows a strong reducing action, and is an extremely preferable additive element in the inner surface sintering joining technique. As the addition amount of phosphorous iron, the solid solubility of P in the Fe—C solid solution is about 1 Therefore, the P content is preferably suppressed to 1.2% by mass or less.

  In the cooling process after the sintered joining, the Fe alloy phase containing carbon is hardened and expanded by martensite transformation, and at the same time, by adjusting the hardenability so that the back metal is not hardened by hardening, the sintered material and It is preferable to apply a compressive residual stress that strengthens the sintered joint.

In addition, the manufacture of sintered sliding members
A method of manufacturing a multi-layer sintered sliding member formed into a cylindrical shape or a substantially cylindrical shape, wherein the collar portion is slid so as to slide on a backing metal made of a cylindrical or substantially cylindrical iron-based material under a thrust load. It is preferable to sinter and bond the iron-based sintered sliding material to the inner diameter surface of the back metal, and at the same time, join the wear-resistant material and / or the sliding material to the flange sliding surface.

  Here, the wear-resistant material and / or the sliding material may be a high carbon high Cr iron alloy sintered material containing at least 1.5 to 3.5% by mass of carbon and 5 to 17% by mass of Cr.

  Further, in the present invention, in the cylindrical and / or cylindrical composite sintered sliding member with a flange, a lubricating oil pool groove is formed in advance on the back metal surface to be sintered and bonded to the sintered material, Lubricating oil can be stored by sintering and bonding to the inner diameter surface, and the oil content of the composite sintered sliding member is increased in the oil impregnation step. Further, in a bearing having such a lubricating oil reservoir, there is no need to form a large amount of pores that extremely reduce the strength in the sintered layer itself as 15% by volume unlike conventional oil-impregnated bearings. It is only necessary to guarantee an open porosity so that a certain lubricating oil is supplied to the sliding surface through the pores in the sintered layer. Therefore, the open porosity in the sintered layer is sufficiently guaranteed. The sintered layer can be densified to about volume%, and a high-strength oil-impregnated sintered bearing can be provided.

  In the present invention, not only high surface pressure due to impact force, but also excellent seizure resistance during rotation and / or rocking sliding in a state where a thrust load is applied, wear resistance against intrusion of earth and sand and sealing function It is possible to provide a hooked working machine bush to which is added. In particular, in terms of cost, when the iron-based sintered sliding material is sintered and joined to the cylindrical inner surface of the cylindrical multi-layered iron-based sintered member with a flange, it depends on the thrust portion sliding environment of the flange. Various types of sliding materials such as carbide, stellite, iron-based wear-resistant materials, ceramics, Cu-based wear-resistant materials, and wear-resistant materials are brazed to the iron-based material that serves as the back metal, and then sintered and infiltrated. It is preferable.

  In the examples described below, Fe-3 mass% C-15 mass% Cr-2.3 mass% Mo-2.1 mass% Ni-0.2 mass% P high carbon high Cr iron-based wear resistance Although the sintered material was sintered and joined, the sintered material is a material excellent in durability as a floating seal material for a lower roller roller portion of a construction machine.

  Next, specific examples of the copper-based sintered sliding material and the sintered sliding member using the same according to the present invention will be described with reference to the drawings.

Example 1
Using electrolytic iron (99.95% by mass), Al, and Co, alloys of various compositions are melted and manufactured in a vacuum atmosphere, forged, cut into small test pieces, and the magnetic transformation temperature (Curie point) of these alloys. The relationship between hardness and heat treatment was investigated.

  1 (a) and 1 (b) show that a Fe—Al—Co ternary alloy having a composition of 0 to 40 atomic% Co and 0 to 40 atomic% Al is heated to 1200 ° C. and then rapidly cooled (a), and The respective Vickers hardness distributions of (b) subjected to aging treatment at 600 ° C. for 10 hours after quenching are shown. From these figures, a slight hardening tendency is observed in the range of 25 to 40 atomic% Al and 15 to 30 atomic% Co in the rapidly cooled one (FIG. 1 (a)). In FIG. 1 (b)), it can be seen that there are regions that harden significantly in the range of 15 to 40 atomic% Al and 10 to 40 atomic% Co.

  Next, FIG. 2 shows the relationship between the Al concentration (atomic%) and the hardness in the 0, 10, 15, 20, 30, 40 atomic% Co cross section in FIG. This figure shows the following. That is, in 0 atomic% Co (when Co is not added), it hardens as the Al concentration increases. Since this hardening rate is approximately equal to the degree of increase observed for the quenched alloy, almost no age hardening phenomenon at 600 ° C. has been observed. On the other hand, in 10 atomic% Co, it hardens | cures notably in 15 atomic% Al (about 8 mass% Al), and after reaching the maximum hardness (Hv = 620) in 20 atomic% Al, it is 30 atoms Age hardening disappears at% Al. Further, the effect of Al addition at 20 atomic% Co was confirmed to be age hardenability from 10 atomic% Al, and after reaching the maximum hardness (Hv = 770) at 30 atomic% Al, it was almost at 40 atomic% Al. Age hardening disappears. Further, in 30 atomic% Co, age hardenability is confirmed up to 40 atomic% Al. However, when 40 atomic% Al is reached, remarkable age hardenability is lost.

  From the above results, it is preferable to adjust in the range of 10 to 30 atomic% Co and 10 to 50 atomic% Al in order to efficiently exhibit the age-hardening property due to the addition of Co. It is clear that the age-hardening property of is also exhibited at a low Al and low Co concentration side of, for example, about 5 atomic%. In addition, it is clear that the remarkable age hardening phenomenon due to the addition of Co as described above is derived from the two-phase separation reaction of the Fe-based ordered phase, and the same phenomenon has been confirmed in the Fe-Al-Ni-based alloy. ing. Furthermore, it is thermodynamically predicted that the same phenomenon can be obtained by using Si and Co instead of Al, and Mn alloy elements instead of Ni.

FIG. 3 shows the magnetic transformation temperature (Curie temperature) and Al atoms of a Fe—Al—Co ternary alloy added with 10 atomic% Co, obtained from a magnetization curve measured at a temperature rising / falling rate of 5 ° C./min. The relationship with% concentration is shown. The figure also shows the results of investigating the orderly irregular transformation temperature of Fe ₃ Al described in the HANSEN phase diagram by measurement methods such as thermal analysis, specific heat, electrical resistance, and magnetic transformation method. . In general, the method for measuring the disordered and irregular transformation temperature from the magnetic transformation measurement is low in sensitivity. However, when the results obtained by other measuring methods are combined, the disordered and irregular transformation of Fe ₃ Al in the Fe—Al alloy system is 500. The Al concentration limit occurring at ℃ is 10 atomic% (about 5 mass%), and as described above, regular irregular transformation occurs even at room temperature, and the sliding surface temperature is immediately achieved at 100 to 200 ℃. In consideration of the above, as shown by the broken line in FIG. 3, it is clear that the Al concentration limit at which the irregular disorder transformation occurs is about 4 atomic% (about 2 mass%). Therefore, it can be seen that the addition of at least 4% by mass or more is preferable in order to effectively use the clear irregular disorder transformation.

Further, a plurality of magnetic transformation points appear in Fe-10 atomic% Co-15 atomic% Al, and a three-stage magnetic transformation temperature is confirmed in an Fe-10 atomic% Co-20 atomic% Al alloy. From this, it is confirmed that there are three types of atomic arrangements of the disordered state, Fe ₃ Al type and FeAl type, and a plurality of magnetic transformation point appearance regions due to the ordered phase are more Since it is expressed by transitioning to a lower concentration side of Al, the addition of Co stabilizes the Fe-Al-based ordered phase. In this case, the appropriate amount of Al addition is 1% by mass or more, It is clear that with further Co addition (˜40 atomic%), the proper amount of Al addition is reduced to 0.5 mass%.

(Example 2)
In this example, in order to evaluate the wear resistance of the Fe ordered phase alone, a cylindrical test piece having a diameter of 10 mm and a length of 50 mm made of a melted material having the composition shown in Table 1 was used. After adjusting various hardnesses by adjusting the aging treatment time at 600 ° C., the sediment wear resistance when pressing a sliding material against a Portland cement disc containing 20% by mass of SiC under oil lubrication evaluated.

  FIG. 4 shows a conceptual diagram of the test apparatus and test conditions. In this test, the S45 reference material quenched and tempered so that the Vickers hardness is Hv = 500 is attached to the apparatus simultaneously with the test material, and the wear property of the test material is determined by the ratio of the wear amount to the wear amount of the reference material. evaluated. FIG. 5 shows the test results showing the hardness of the Fe-based ordered phase material according to the present invention together with the comparative material. This figure clearly shows that the wear resistance of the Fe-based ordered phase is extremely excellent for the hardness. It is clear that these results are the same even when each alloy is manufactured as a sintered material containing a porosity of 0.1% by volume or more.

(Example 3)
In this example, the alloy shown in Table 2 was vacuum-melted, processed into a plate shape by hot forging at 1000 to 1150 ° C. and hot rolling, then cut and round bent, and the shape shown in FIG. The bushes machined in the above were used as sliding test pieces, and adjusted to have various hardnesses by adjusting the aging treatment time at 600 ° C. As comparative materials, carburized bushing (comparative material 1), surface carbon concentration adjusted to about 0.8% by mass on SCM420 case-hardened steel, S43C quenching and tempering bush (comparative material 2), and high-strength brass 4 type material (Cu −25 mass% Zn-5 mass% Al-3 mass% Mn—2.5 mass% Fe) (Comparative material 3) was used.

FIG. 7 shows a conceptual diagram and test conditions of the sliding test apparatus. In this sliding test is going to increase the sliding surface pressure in stages while reciprocation of 10000 times every 100 kg / cm ² to 1000 kg / cm ² with respect to the projected area of the test bushing, with baked When the coefficient of friction suddenly increased or when sudden wear or abnormal noise occurred, the test was interrupted for evaluation.

  FIG. 8 shows the transition of the sliding friction coefficient, and FIG. 9 shows the transition of the sliding wear amount. From these test results, it is clear that the material of the present invention exhibits extremely good seizure resistance as compared with the comparative material, and the wear resistance is improved when the Fe ordered phase is age-hardened. It is clear that this result can be applied to a high-density sintered sliding material having a porosity as low as possible.

Example 4
Fe atomized powder of 300 mesh or less, Fe 10 mass% Al, Fe 17 mass% Al atomized powder, Al atomized powder, Sn atomized powder, Ni10P atomized powder, Cu8P atomized powder, TiH powder of 300 mesh or smaller, phosphorous iron (25 mass% P ), Si powder, Mn powder, 5 μm carbonyl Ni powder, graphite having an average particle diameter of 6 μm, etc., were used to prepare mixed powders of the blending components shown in Tables 3 and 4, and tensile test pieces shown in FIG. (Shape bush sliding test piece) was molded at a molding pressure of 4 ton / cm ² . In addition, these compacts were sintered for 10 minutes to 1 hour in the range of 950 to 1250 ° C. in a vacuum state of 10 ⁻¹ torr or less, and their dimensions and structure were examined after cooling N ₂ gas of 600 torr.

  11 to 13 show the lengths of the tensile test pieces when vacuum-sintered at 1140 ° C., 1200 ° C., and 1250 ° C. for 1 hour each. Other detailed dimensional measurement results are also shown in Tables 3 and 4. As is clear from this result, a sintered body in which Fe and Al powders are blended in an Fe-Al binary sintered alloy with respect to the compact length (about 96.55 mm) indicated by a broken line in the figure. Bonding gold does not shrink at high temperatures up to 1250 ° C., and is a conventional report (eg DJ LEE AND RM German, American Power Metallurgy Institute, 21 (1985. 9)). As shown in FIG. In addition, even in a sintered alloy in which Si, Sn, and C, which have thermodynamic repulsion properties with respect to Al, are added alone, significant expansion is not suppressed, and phosphorous iron (Fe 25 mass% P) is used alone. Sintering shrinkage was observed at 1250 ° C. only when added. Therefore, in order to obtain a dense Fe—Al binary sintered alloy, it is apparent that a small amount of Al powder is preferably added to the Fe—Al binary alloy powder or binary alloy powder (Table 3). No. 32 of Table 4).

  However, as a result of investigating the influence of Cu addition for improving the difficulty of sinterability of Fe—Al sintered alloy using elementary powder, the addition of Cu alone hardly improves the sintering shrinkage at less than 10% by mass. However, it has been found that the addition of 10% by mass or more allows the sintering shrinkage to be recognized, and preferably about 20% by mass Cu ensures sufficient sintering shrinkage. As can be seen from the structure observation photograph of the Fe-12 mass% Al-20 mass% Cu sintered alloy shown in FIG. 14, a large amount of Cu is dissolved in the Fe—Al alloy phase. This is because the amount of the Cu—Al-based alloy remaining as a liquid phase between the Al alloy phase particles is reduced. Therefore, in order to improve the sinterability of the Fe—Al based sintered alloy, it was found that addition of 10% by mass or more of Cu is necessary, and more preferably 20% by mass or more.

  Furthermore, by adding alloying elements that lower the melting point of Cu alloys such as Si, Sn, P, and Ti together with Cu, the sintering shrinkage is further improved, and the sintering shrinkage from the lower temperature side is ensured. You can see that In addition, in the sintered alloy in which carbon is dissolved, the sinterability is further improved, but this is because a large amount of Cu is generated in the liquid phase by reducing the solid solubility of Cu in the Fe alloy phase. It is because it became.

  Table 5 shows the numbers in Table 3 and Table 4. The chemical composition of the Fe-Al ordered phase and the Cu-Al ordered phase connecting the Fe-Al ordered phase obtained by sintering the 23-27 sintered alloy at 1200 [deg.] C. for 0.5 hr under vacuum and gas cooling was measured using an X-ray microanalyzer (EPMA). This shows the results of investigation by (analysis).

  As is apparent from Table 5, Al and Ti are significantly concentrated in the Fe-Al ordered phase rather than the Cu-Al phase, Sn is concentrated in the Cu-Al phase, and Fe is contained. It was found that about 3 to 5% by mass was dissolved. In addition, when referring to the phase diagram of HANSEN, the Cu-Al phase contains about 9% by mass of Al, and further contains elements that stabilize the β phase, such as Sn and Fe. It was found that the -Al phase is considered to correspond to the β phase.

  Furthermore, the Fe-Al alloy phase also contains up to 25% by mass of Cu depending on the sintering temperature, and the Fe-Al alloy phase is cooled by the cooling process after sintering or reheating on the low temperature side below the sintering temperature. It is clear that a fine Cu alloy phase corresponding to the β phase is also precipitated.

  This is because, as already disclosed in Japanese Patent Application Laid-Open No. 2001-271129 by the present applicant, β-phase Cu—Al alloys are used under extremely severe oil lubrication conditions with high surface pressure and low sliding speed. It is clear that it is extremely preferable because it exhibits excellent sliding properties and wear resistance.

  As already disclosed in Japanese Patent Laid-Open No. 2001-271129, the addition of Si, Sn, and Ti significantly enhances the sinterability of the β-phase Cu—Al alloy and at the same time significantly hardens it. For this reason, it is preferable that the addition amount be 10% by mass or less with respect to the addition amount of Cu.

  FIG. 15 shows the influence of Si, Co, and Ni on the sintering shrinkage of an Fe—Al based sintered alloy using Fe, Al elementary powder. From this figure, it can be seen that sufficient sintering shrinkage can be obtained by addition of Ni and Co that make the age hardenability remarkable, and that the sintering shrinkage can be further improved by addition of Si. Since Si is an element that forms an Fe—Si-based ordered phase having the same crystal structure as Al, complex addition with Al is an extremely desirable element from the viewpoint of forming an ordered phase.

  Further, FIG. 15 shows the sintering shrinkage of a regular phase sintered alloy (No. 32 in Tables 3 and 4) in which the amount of Al powder added is suppressed using Fe 10 mass% Al alloy powder. However, it exhibits good shrinkage compared with a sintered alloy consisting of only elementary powders, and is not suitable for alloy powders such as Fe-Al, Fe-Co-Al, Fe-Ni-Al, and Fe-Al-Si. When the availability is good, it is clear that various Fe—Al based sintered alloys having good sintering shrinkage can be obtained by adding and blending Cu or Cu alloy powder to these alloy powders.

(Example 5)
In this example, the representative Fe—Al sintered alloys in Tables 3 and 4 shown in Example 4 and a Cu alloy matrix as shown in Table 6 were used for Fe15Al, Fe10Al10Co, Fe0 of # 100 mesh or less. .6 C4Al0.74Mn1.51Cr0.38Mo The alloy was investigated so as to disperse the sliding characteristics of the alloy powder so as to be dispersed. In addition, as a comparative material, high strength brass 4 type material (Cu-25 mass% Zn-5 mass% Al-3 mass% Mn-2.5 mass% Fe) and No. A 53 oil-based oil-impregnated bearing was used.

The press-molded body was vacuum-sintered so that the porosity was about 10% by volume and 20% by volume after molding a cylindrical body having an outer diameter of 66 mm, an inner diameter of 47 mm, and a height of 35 mm with a pressure of 4 ton / cm ² . those bush processed those N ₂ gas cooling into the shape shown in Figure 6 above, and were subjected to the sliding test 600 impregnated with a # 30 lubricating oil having been subjected to the heat treatment of 1hr at ° C.. The sliding test apparatus and its test conditions are as shown in FIG. Suridomen圧stepwise increasing the surface pressure while reciprocation of 10000 times per 50 kg / cm ² to 1000 kg / cm ² with respect to the projected area of the test bushing, or friction coefficient with baked rapidly increases The test was interrupted and evaluated when sudden wear or abnormal noise occurred.

  FIG. 16 shows the test results when the porosity is adjusted to about 10% by volume. As is apparent from this result, it can be seen that many of the materials of the present invention show significantly higher seizure-resistant surface pressure than the high strength brass material. In particular, Fe-Al-Cu and Fe-C-Al-Cu that do not contain Co, Ni, etc. have superior seizure resistance compared to that shown in FIG. It is clear that this cause is caused by the lubricating oil impregnated in the sintered body, and it is clear that a porosity of 5% by volume or more that maintains at least open porosity is desirable. No. From the results of 47 to 57, the seizure resistance is remarkably improved even in the sliding material in which the Fe—Al ordered phase is dispersed in the Cu matrix, and the improvement effect is obtained when the Fe-based ordered phase is about 5% by mass or more. However, it is understood that it is desirable to contain 10% by mass or more (approximately 10% by volume or more).

  No. The Fe-C-Al ordered phase alloy of 53 to 55 has an Al concentration as low as 4% by mass, but is hardened and hardened by gas cooling after sintering, and its hardness is Hv450 or more, thereby preventing seizure resistance. It can be seen that the performance is improved.

  Furthermore, no. No. 57 is a copper sintered matrix composition having a β-phase Cu—Al alloy, but it can be seen that it exhibits extremely excellent sliding characteristics.

  FIG. 17 shows a sliding test result when the porosity is adjusted to about 20% by volume, and it can be seen that the seizure resistance is further improved. In reality, when a porosity of 25% by volume or more is maintained, insufficient strength as a bearing material is considered to be a problem.

  From the results of the above examples, it has been clarified that the Fe alloy phase itself has extremely excellent seizure resistance and wear resistance such as wear resistance and wear resistance. A copper-based sintered sliding with a structure in which a large amount of Cu is added to the Fe ordered phase by the Cu phase and a structure in which the amount of Cu is increased and the Fe alloy phase is dispersed in the Cu phase. It is possible to develop materials. In this case, the amount of the Fe—Al-based alloy phase dispersed in the copper-based sintered sliding material is considered to be 10% by volume or more, more preferably 20% by volume or more and 50% by volume or less. Is clear.

(Example 6)
Table 7 shows the composition of the Fe-based ordered phase sintered alloy used in this example. The mixed powder was formed by forming a cylindrical body having an outer diameter of 53 mm, an inner diameter of 47 mm, and a height of 35 mm with a pressing force of ² ton / cm ² , and then an inner diameter portion of a steel pipe (S45C) having an outer diameter of 66 mm, an inner diameter of 53 mm, and a height of 40 mm. Was set at 1150 ° C. and vacuum sintered at 1150 ° C. for 1 hour, and then N ₂ gas was cooled.

  In Table 7, the joining ratio (joining area ratio) between the steel pipe and the sintered layer evaluated by the ultrasonic inspection apparatus is also shown. As is apparent from this table, it can be seen that the addition of Sn is extremely effective also for the inner diameter sintered joining, and the addition of 0.2% by mass or more, preferably 0.5% by mass or more is necessary. It can also be seen that the joining rate is remarkably improved by the addition of phosphorous iron, Ti, Cr, and Ni. This is apparently because these elements improve the wettability of the surface of the steel pipe that circumscribes the liquid phase generated during sintering. In addition, the decrease in the bonding rate due to the addition of graphite alone was not recognized greatly because the liquid phase containing a large amount of graphite and Sn was difficult to wet, so that the liquid phase generated in the sintered body was bonded to the steel pipe. However, when graphite and an alloy element rich in reactivity with graphite such as Ti and Cr are added in combination, the influence of graphite on Sn having a low melting point precedes. It has been found that the bonding property is further improved by the action of Ti and Cr overlapping.

  Also, B12, 13, 14, and 15 were subjected to sintered joining of iron-based sintered alloy to which graphite particles obtained by granulating SGO graphite with a diameter of 0.05 to 0.85 mm with water glass for solid lubrication were added. However, the addition of Al increases the remarkable sintering joining property. It is clear that this is due to the expansion of sintering due to the addition of Al.

  Furthermore, for the inner diameter surface of the steel pipe to be joined, a spiral oil groove having a depth of about 1 mm and a width of 5 mm is machined and bonded to the inner diameter surface in the same manner as described above. You can see that you can. Moreover, it turns out that it is suitable for a non-greasy bearing for a long time by devising this groove processing part suitably and making this groove part contain lubricating oil.

(Example 7)
In this example, Cu atomized powder of 250 mesh or less, Sn atomized powder, Fe15Al, Fe10Al10Ni, Fe0.6C4Al0.74Mn1.51Cr0.38Mo atomized powder of 100 mesh or less are shown in Table 6 of Example 5. The mixed powder was prepared, and a bonding sintering experiment was performed on a mild steel plate (SS400, thickness 3.5 mm, width 90 mm, length 300 mm), which was roughened with No. 400 polishing paper and thoroughly washed with acetone.

  In this experiment, the mixed powder in Table 6 was sprayed on the mild steel plate at a height of 3 mm, and bonded and fired so as to be heated at 850 ° C. for 20 minutes in an ammonia decomposition gas atmosphere furnace having a dew point of −38 ° C. After ligation, the sintered layer was rolled with a rolling mill so as to have a thickness of 1.7 mm, and the rolled sprayed material was again sintered under the same conditions as described above. In addition, No. Nos. 53 to 55 were manufactured at a sintering temperature of 950 ° C. No. 57 uses metal Al powder, and it can not be produced by the spreading method, so it cannot be manufactured. Therefore, Cu20Al alloy powder of 300 mesh or less is sintered at 900 ° C. using mixed powder adjusted to the same amount as Al concentration. Manufactured by. After this sintering, a round bending process was performed on a direct cylinder of 45 mm with the sintered layer inside, and the peeling state of the sintered layer from the steel plate at that time was observed. As a result, no cracks or peeling occurred during bending.

(Example 8)
In this example, the mixed powder shown in Table 8 was prepared using Fe atomized powder of 100 mesh or less, Cu atomized powder of 250 mesh or less, Sn atomized powder, Fe15Al, Fe10Al10Ni atomized powder of 100 mesh or less, and Example The joint sintering experiment to the same steel plate as 7 was carried out. In addition, the sintering temperature was 900 degreeC, and the peeling condition of the sintered layer after a round bending process was observed. There was no occurrence of thin profits in this observation.

  Next, the sliding characteristics were investigated using the constant speed friction and wear tester and test conditions shown in FIG. 18 and the sliding test piece shown in FIG. As a comparative material, a Cu-10 mass% Sn-10 mass% Pb lead bronze sintered material (LBC) bonded and sintered on a steel plate was used. FIG. 20 shows the result of investigating the PV value (limit PV value) at the time when abnormal wear and an abnormal increase in friction coefficient occur. From this result, it is clear that the addition of 5 mass% or more Fe15Al ordered phase alloy powder improves the sliding characteristics, but the addition of 10 mass% or more is more preferable.

Example 9
In this example, tests were performed on the production of sintered material by the infiltration method and the joining to the inner diameter of the steel pipe. In this example, a mixed powder of iron-based sintered material shown in Table 9 was formed into a press-molded body under the same conditions as in Example 6 above, and mixed powder adjusted to have a composition of Cu, Cu20Sn, Cu20Sn22Al2Ti. A compact was prepared and infiltrated simultaneously with sintering in a vacuum atmosphere at 1150 ° C.

  The dimensional change rate and porosity of the iron-based sintered material after infiltration are shown in Table 9. In each case, the expansion is significant, and the porosity is sufficiently high from the viewpoint of the strength of the sintered body. It turns out that a high thing is obtained. In particular, it is apparent that this is a preferable sliding material for a material to which granulated graphite for solid lubrication is added in the same manner as in Example 5.

  In addition, when a press-molded body of an iron-based sintered material is placed on the same back metal as in Example 6 and infiltrated, it is joined to the inner surface of the back metal as easily imagined. I understood.

(Example 10)
Using B12 to 15 produced in Example 6 and D4, 9, 11, and 12 produced in Example 9, the oil impregnation treatment was performed in the same manner as in Example 3, and then a sliding test was performed. All the test pieces used in this example were adjusted so that they were quenched and hardened by quenching after sintering or infiltration, and were adjusted to a hardness of Hv450 or higher.

Furthermore, as a result of the preliminary test, it was found that the end face portion of the test piece of B12 to 15 may be chipped at a surface pressure of 500 kgf / cm ² or more. Therefore, the test piece used in this example is an oil groove on the inner peripheral surface. The processing was stopped, and the inner peripheral surfaces of both end surfaces were chamfered by 30 ° from a position 3 mm from the end surface.

  FIG. 21 shows the result of the sliding test. B12, B13, and D12 with a small Al addition amount are seized at a relatively low surface pressure, but an improvement in seizure resistance due to the dispersion of the graphite lubricant is clearly observed as compared with the result of FIG. Further, it is clear that the improvement in seizure resistance of B14, B15, D4, D9, and D11 to which 4% by mass or more of Al is added is remarkable.

A diagram showing the Vickers hardness distribution of a Fe-Al-Co ternary alloy heated to 1200 ° C. and then rapidly cooled, and a diagram showing the Vickers hardness distribution of this aging treated at 600 ° C. for 10 hours after this rapid cooling (b) Graph showing the relationship between Al concentration (atomic%) and hardness in 0, 10, 15, 20, 30, 40 atomic% Co cross section in FIG. The graph which shows the regular disorder transformation area of a Fe-Al type alloy phase Conceptual diagram of test equipment for wear test and diagram showing test conditions Graph showing the relationship between hardness and wear ratio of Fe-based ordered phase material Sectional view showing the shape of the test piece subjected to the sliding test Schematic diagram (a) and test condition (b) of sliding test equipment Graph showing the transition of sliding friction coefficient of Fe-based ordered phase material Graph showing the transition of sliding wear amount of Fe-based ordered phase material Diagram showing shape of tensile test piece Graph showing FeAlCu-based sintering characteristics (1140 ° C) Graph showing FeAlCu-based sintering characteristics (1200 ° C) Graph showing FeAlCu-based sintering characteristics (1250 ° C) Photographs showing sintered structures (metal structures) of various Fe-based ordered phase sintered alloys Graph showing the influence of Si, Co, Ni on the sintering shrinkage of Fe-Al ordered ordered sintered alloys Graph showing seizure resistance (porosity of about 10% by volume) of F system ordered phase sintered alloy Graph showing seizure resistance (porosity of about 20% by volume) of F system ordered phase sintered alloy Diagram showing constant speed friction and wear tester and test conditions Diagram showing the shape of sliding test piece for constant speed friction and wear test Graph showing the sliding characteristics of Fe-based sintered materials Graph showing seizure resistance of graphite dispersed sliding material

Claims (7)

A copper-based sintered sliding material comprising a sintered structure in which a Cu-Al-based alloy phase is used as a grain boundary phase to connect an Fe ordered phase,
The Cu—Al-based alloy phase includes Al: 6.25 to 9.85% by mass, Sn: 3.71 to 16.79% by mass , Ti: 0.08 to 1.52% by mass, and Fe: 2.36 to 5.45 mass%, P: 0.05 to 0.13 mass%, Cu: 69.92 to 83.86 mass%, and β described in the Cu-Al phase diagram Comprising a phase and / or its transformation phase,
The Fe ordered phase, Al: the 12.32 to 16.42 mass%, Cu: and 14.33 to 22.74 wt%, P: and 0.07 to 0.13 wt%, Sn: 0.26 and 0.7 mass%, Ti: and 0.18 to 1.01 wt%, Fe: copper-based sintered sliding material characterized by consisting of from 59.18 to 72.36 wt%. A sintered sliding member, wherein the copper-based sintered sliding material according to claim 1 is formed and processed into a cylindrical shape or a plate shape and integrated with a back metal made of an iron-based material. The hardenability of the iron-based material used as the back metal is a DI value of 2.0 or less, and shows a structure of ferrite, pearlite, or bainite even by gas quenching or oil quenching. The sintered sliding member according to claim 2 , wherein compressive residual stress acts on the copper-based sintered sliding material by converting a part or more of the Fe alloy phase in the sintered sliding material into martensite. The sintered sliding member according to claim 2 or 3 , wherein a porosity of the iron-based material serving as the back metal is adjusted to 3 to 20% by volume, and each pore is impregnated with a lubricating oil. A multi-layered sintered sliding member formed in a cylindrical shape, and a flange portion is provided on the back metal so as to slide under a thrust load, and a wear- resistant material and / or a sliding surface is provided on the sliding surface of the flange portion. The sintered sliding member according to any one of claims 2 to 4 , wherein a moving material is disposed. The wear-resistant material or sliding material is a kind of carbide, stellite, iron-based wear-resistant material, ceramics, Cu-based wear-resistant material, these are sprayed, brazed, sintered bonded, infiltration bonded, The sintered sliding member according to claim 5 , wherein the sintered sliding member is integrated by any means of adhesion. The sintered sliding member according to claim 5 , wherein the copper-based sintered sliding material is integrated on the flange sliding surface.