JP4574129B2 - Method for manufacturing composite structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a composite sintered body in which a fibrous core material is coated with a skin material, a composite structure in which it is assembled, and a method for manufacturing the same.
[0002]
[Prior art]
Conventionally, in order to improve the toughness as well as the hardness and strength of the material, the outer peripheral surface of the long core formed of a sintered body of metal oxide, carbide, nitride, carbonitride, etc. Studies on composite sintered bodies covered with a skin material made of a sintered body have been made, and for example, proposed in Patent Documents 1 and 2. In these documents, a composite sintered body composed of an assembly of composite fiber bodies composed of a core material and a skin material has a high hardness by increasing the fracture resistance of the structure without increasing the hardness and increasing the toughness. It is described that a structure having high toughness can be realized.
[0003]
[Patent Document 1]
US Pat. No. 5,645,781
[0004]
[Patent Document 2]
US Pat. No. 6,063,502
[0005]
[Problems to be solved by the invention]
However, since the composite fiber body of Patent Documents 1 and 2 has a relatively large fiber diameter of the core material, the arrangement of the core material and the skin material of the composite sintered body can be made uniform. For example, when using a composite fiber body having a thin fiber diameter when using a composite sintered body for a relatively small member such as a cutting tool, the fibers are aligned when the composite fiber body is inserted into the extruder one by one. Since the state deteriorates, as a result of the heterogeneous alignment state of the fibers in the formed converging composite fiber body, as shown in FIG. 9, the skin material aggregated portion in which the skin material is aggregated into a large lump as shown in FIG. There was a problem that the strength was reduced.
[0006]
Accordingly, an object of the present invention is to uniformly form a converging composite molded body obtained by bundling a plurality of composite fiber bodies composed of a composite fiber body core material and a skin material having high strength and toughness, and a composite sintered body obtained by firing the same. An object of the present invention is to provide a high-toughness and high-strength composite sintered body that is manufactured with a simple structure and sufficiently reflects the characteristics of the composite fiber body in the composite sintered body, and is practical and highly reliable.
[0007]
[Means for Solving the Problems]
In producing a composite sintered body having a multifilament structure in which a plurality of the composite fiber bodies are converged, the inventor combines a single filament-like composite fiber body that has been once extruded into an extruder. A bundled body is produced by bundling a plurality of fiber bodies in a state where they are aligned in a mold that can be set parallel to the fiber direction, and the bundled body is loaded into an extrusion molding machine. As a result of being able to reduce the fiber diameter and reducing the agglomerated part of the skin material, it has been found that it has excellent toughness and strength, and this makes it possible to take advantage of the composite fiber body and to have excellent fracture resistance and strength It was found that a sintered body can be formed.
[0008]
  That is, the composite sintered body of the present inventionManufacturing methodIs(A) A step of producing a composite fiber body in which a skin material molded body having a composition different from that of the core material molded body is coated around the fibrous core material molded body by coextrusion molding; b) A plurality of the composite fiber bodies obtained by the step (a) are bundled in a state in which the composite fiber bodies are aligned in a mold that can be set in parallel to the fiber direction, and the plurality of composite fiber bodies are formed into the molds 80- A step of producing a converged molded body by applying vibration in a state heated to 200 ° C. to correct warpage of each composite fiber body and aligning them, and then pressing the converged composite fiber bodies by press molding. And (c) a step of producing a converged fiber molded body in which a plurality of the composite fiber bodies are converged and stretched by loading into the extrusion molding machine the extruded molded body obtained in the step (b) and performing extrusion molding. And (b) the bundled fiber molded body obtained in steps (d) and (c). A step to prepare a set molded body obtained by a plurality of sets, baking, the
Comprising
A first ceramic comprising at least one oxide, carbide, nitride and carbonitride selected from the group consisting of Group 4a, 5a and 6a group metals, aluminum and silicon in the periodic table;
Periodic Tables 4a, 5a and 6a Group 1st hard particles composed of one or more of carbides, nitrides and carbonitrides of 65a to 98% by mass and at least 1 selected from the group of iron, cobalt and nickel A first hard sintered body obtained by bonding seed bonding metals at 2 to 35 mass%,
A diamond sintered body obtained by bonding 60 to 99% by mass of diamond with a binding metal of 1 to 40% by mass of an iron group metal;
Alternatively, 20 to 99% by mass of cubic boron nitride is added to the periodic table 4a, 5a, 6a group metal and silicon, aluminum carbide, nitride, carbonitride, boronide and oxide, and one type of iron group metal. A cBN sintered body formed by bonding at 1 to 80% by mass of the binder composed of the above,
Composite sintering in which a plurality of composite fiber bodies each covered with a skin material having a composition different from that of the core material around a fibrous core material made of An area Ss of the skin material with respect to an area Sc of the core material in the composite sintered body, wherein the core material has a diameter of 5 to 50 μm, and is a composite structure having a structure in which a plurality of bodies are assembled. Ratio (Ss / Sc) is 30% or less, and in an arbitrary area of 100 μm × 100 μm in the composite sintered body, the thickness d is 3 or more in terms of the ratio (d / Ds) to the diameter Ds of the core material A composite structure in which there is no skin material agglomerated portion and the thickness d of the skin material agglomerated portion is 3 or less in terms of the ratio (d / dm) to the average thickness dm of the skin material is produced.It is characterized by this.
[0009]
  Here, the thickness d of the skin material aggregated portion is 3 or less in terms of the ratio (d / dm) to the average thickness dm of the skin material in terms of increasing the strength as a composite sintered body.is important.
[0010]
Furthermore, the composite structure of the present invention having a structure in which the composite sintered bodies are further assembled is a structure excellent in toughness and strength.
[0012]
  Here, in the step (b), the mold in which the plurality of composite fiber bodies are aligned is shaken in a state heated to a temperature of 80 to 200 ° C.MoveAfter giving and correcting the warp of each composite fiber body, the converged composite fiber bodies are pressure-bonded together to produce a converged molded body, thereby producing a more aligned focused molded body and composite sintered body Thus, the composite sintered body can have a more uniform structure.
[0013]
  When producing this converging molded body, the converging molded body in which the converging composite fiber bodies are pressure-bonded to each other is produced by press molding in a state where the mold is heated to 80 to 200 ° C. By fixing the bodies together, it is possible to produce a more aligned focusing molded bodyis important.
[0014]
Further, a composite structure having a uniform structure can be produced by further collecting the bundled fiber molded bodies obtained in the step (c) to produce a bundled aggregate molded body.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
  Of the present inventionConstructing a composite structure obtained by a method for producing a composite structureThe composite sintered body will be described in detail below based on the drawings.
[0016]
  According to FIG., DoubleIn the composite sintered body 10, a plurality of composite fiber bodies 13 (see FIG. 1A) in which a skin material 12 having a composition different from that of the core material 11 is coated are collected around the fibrous core material 11. It consists of a structure.
[0017]
  According to the present invention, as shown in FIG. 2, the diameter Ds of the core material 11 is 5 to 50 μm, and the ratio of the area Ss of the skin material 12 to the area Sc of the core material 11 occupying in the composite sintered body 10 (Ss / Sc) is 30% or less, and in an arbitrary 100 μm × 100 μm cross section in the composite sintered body 10, the thickness d is 3 or more in the ratio of the core material diameter Ds (d / Ds). 15And the thickness d of the skin material aggregated portion is 3 or less in terms of the ratio (d / dm) to the average thickness dm of the skin material.Thus, the composite sintered body 10 can have high toughness and high strength.
[0018]
  That is, when the diameter Ds of the core material 11 is smaller than 5 μm, the effect of the composite is impaired, the toughness is lowered, and a uniform structure cannot be maintained, and a skin material aggregation portion 15 described later.ExistAnd uneven structure. Moreover, when the area Ss of the skin material 12 / the area Sc of the core material 11 exceeds 30%, the content ratio of the core material 11 that should bear the hardness and strength decreases, and the hardness, strength, toughness, etc. of the composite sintered body 10. It becomes difficult to control and optimize the characteristics.
[0019]
The area ratio between the core material 11 and the skin material 12 indicates a value calculated by an image analysis method in a cross-sectional photograph including 10 or more composite fiber bodies 13 in an arbitrary cross section of the composite sintered body 10. Further, the diameter Ds of the core material 11 can be calculated on the assumption that the core material 11 is a circle from the value obtained by dividing the area Sc by the number of the core materials 11 present in the photograph. Since the surface perpendicular to the major axis direction of the fibrous body 13 is not necessarily captured, in the present invention, the length (minor axis) in the direction orthogonal to the longest length (major axis) of each core material 11 is determined. Is estimated as the diameter of the core material.
[0020]
Further, according to the present invention, when the number of the skin material aggregation portions 15 exceeds 20 within the above range, the strength of the composite sintered body 10 is reduced and the variation becomes remarkable. The number of skin material agglomerated portions 15 is particularly preferably 10 or less, more preferably 5 or less, and even more preferably 0 in order to achieve stable strength. According to the present invention, as shown in FIG. 9, the ratio of the longest length (major axis) L to the length (minor axis) d in the direction orthogonal to the major axis of the skin material is 1. An aggregated state of 5 or less is defined as the skin material aggregated portion 15, and the length of the short axis is defined as the thickness d of the skin material aggregated portion 15. Further, the average thickness d of the skin material 12_mIs an average value when the thickness of the skin material is measured by the same method as described above by selecting between the center points of the adjacent core materials in 20 or more pairs between any adjacent core materials.
[0021]
  Here, the thickness d of each skin material aggregation portion 15 is preferably 3 or less in terms of the ratio (d / dm) to the average thickness dm of the skin material 12 in terms of increasing the strength as the composite sintered body 10, that is, , D / dm> 3 number of skin material aggregation portions 15Is 0Must beis important.
[0022]
Furthermore, it can be set as the composite structure 17 of the predetermined shape which the said multiple sintered compact 10 gathered further, and can be set as the structure excellent in toughness and intensity | strength.
[0023]
The composite sintered body 10 can be assembled by randomly arranging the composite fiber bodies 13 as shown in FIG. 3A to obtain a structure having isotropic characteristics. For example, in order to eliminate the skin material agglomerating portion 15 and obtain a uniform structure of the core material 11 and the skin material 12, the composite fiber body 13 is uniaxially oriented as shown in FIGS. (B), (c), and (d). It is desirable to have a structure arranged in the order.
[0024]
As a material constituting the core material 11 of the composite fiber body 13 used in the present invention, at least one oxide, carbide, nitride, and the like selected from the group of the periodic table 4a, 5a and 6a group metals, aluminum and silicon, and A first ceramic made of carbonitride, among which at least one selected from the group of alumina-zirconia, alumina-titanium carbide (titanium carbonitride), alumina-silicon carbide, silicon carbide, silicon nitride, zirconia, titanium boride, Furthermore, alumina-titanium carbide (titanium carbonitride) or alumina-zirconia can be suitably used. In addition, it is also possible to appropriately include a sintering aid component in the first ceramic.
[0025]
Further, the other material constituting the core material 11 includes first hard particles composed of one or more of carbides, nitrides and carbonitrides of the periodic table 4a, 5a and 6a metals, particularly tungsten carbide, At least one selected from the group consisting of titanium, titanium carbonitride, titanium nitride, tantalum carbide, niobium carbide, zirconium carbide, zirconium nitride, vanadium carbide, chromium carbide and molybdenum carbide, and further tungsten carbide, titanium carbide or titanium carbonitride. At least one selected from the group is desirably 65 to 98% by mass, and this includes at least one selected from the group of iron, cobalt and nickel, in particular 2 to 35% by mass of a binding metal comprising cobalt and / or nickel. 1st hard sintered body, especially cemented carbide or cermet can be used preferably. It is.
[0026]
Further, as still another material constituting the core material 11, in addition to the hard sintered body, 60 to 99% by mass of diamond is combined with 1 to 40% by mass of a binding metal made of an iron group metal, particularly cobalt and / or nickel. A diamond sintered body formed by bonding with can be suitably used. Note that the diamond sintered body can appropriately contain hard particles composed of one or more of carbides, nitrides, and carbonitrides of Group 4a, 5a, and 6a metals of the periodic table.
[0027]
Further, as still another material constituting the core material 11, cubic boron nitride (hereinafter referred to as cBN) 20 to 99 mass% is composed of a periodic table 4a, 5a, 6a group metal, silicon, aluminum carbide, nitriding. A cBN sintered body formed by bonding a material, carbonitride, boride, and oxide with a binding material of 1 to 80% by mass of at least one iron group metal can be suitably used.
[0028]
Of the core material 11, it is desirable to use an alumina ceramic, a diamond sintered body, or a cBN sintered body containing 50 mass% or more of alumina, whereby toughness and wear resistance as the composite sintered body 10 are used. As a cutting tool 1 for cutting steel, cast iron, and heat-resistant alloy, which can be combined, it can be used particularly preferably.
[0029]
On the other hand, as the material of the skin material 12 covering the outer periphery of the core material 11, a hard sintered body or ceramics of a material different from that of the core material 11 is used. Also, metals such as iron, cobalt, nickel, aluminum, silver and gold can be used alone.
[0030]
Further, the combination of the core material 11 and the skin material 12 is, for example, cemented carbide-cermet, cemented carbide-cBN sintered body, cemented carbide-diamond sintered body, cemented carbide-alumina, cemented carbide-nitriding. Silicon, cermet-carbide, cermet-cBN sintered body, cermet-diamond sintered body, cermet-alumina, cermet-silicon nitride, (alumina, titanium carbonitride) -alumina, (alumina, titanium carbonitride) -nitriding Silicon, (alumina, titanium carbonitride)-(alumina, titanium carbonitride), (alumina, zirconia) -alumina, (alumina, zirconia) -silicon nitride, (alumina, zirconia) -silicon carbide, (alumina, zirconia)- (Alumina, titanium carbonitride), (alumina, titanium carbonitride)-(alumina, zirconia), silicon nitride-silicon carbide, Silicon carbide, silicon nitride) -silicon nitride, silicon carbide-diamond sintered body, cBN sintered body-cermet, cBN sintered body-hard metal, and diamond sintered body-hard metal Can be used particularly preferably.
[0031]
On the other hand, the average particle size of the sintered body forming the core material 11, for example, the crystal particles of alumina ceramics, increases the hardness and strength of the composite fiber body 13, and the bonding material (bonding) in the core material 11 and the skin material 12. In view of optimizing the content of the metal and sintering aid), it is preferably 0.05 to 20 μm, particularly preferably 0.1 to 5 μm. On the other hand, the average particle size of the crystal particles forming the skin material 12 is composite. From the viewpoint of improving the toughness of the fiber body 13, it is preferably 0.01 to 5 μm, particularly preferably 0.01 to 3 μm.
[0032]
(Production method)
Next, the manufacturing method of the composite fiber body of this invention is demonstrated. FIG. 4 is a process diagram for explaining a method of manufacturing the composite fiber body 13 of FIG. 1A and the composite sintered body 10 of FIG.
[0033]
In producing the composite fiber body 13, first, the core material molded body 21 is produced. The core material molded body 21 can be basically produced by a known powder metallurgy method, that is, a method in which a raw material powder and a binder (binder) are mixed and molded.
[0034]
As a specific method, the case where alumina ceramics is selected from the above-described core material will be described. First, alumina powder having an average particle diameter of 0.01 to 10 μm is 55 to 80% by mass, particularly 65 to 75% by mass. Then, zirconia powder having an average particle size of 0.01 to 10 μm is mixed in an amount of 5 to 35% by mass and a sintering aid in a ratio of 0 to 10% by mass, and further added with an organic binder, a plasticizer and a solvent. And it shape | molds in cylindrical shape with shaping | molding methods, such as press molding or cast molding, and produces the molded object 21 for core materials (refer Fig.4 (a)).
[0035]
Here, in order to obtain a homogeneous composite molded body by coextrusion molding to be described later, it is desirable that the amount of the organic binder added is 50 to 200 parts by volume, particularly 70 to 150 parts by volume.
[0036]
As the organic binder, paraffin wax, polystyrene, polyethylene, ethylene-ethyl acrylate, ethylene-vinyl acetate, polybutyl methacrylate, polyethylene glycol, dibutyl phthalate, or the like can be used. In order to improve extrudability, lubricating materials such as olive oil, mineral oil, methoxypolyethylene glycol, butyl oleate, and stearic acid may be further added.
[0037]
  On the other hand, the composition is different from that of the core molding 21.Skin materialThe two materials having a half-cylindrical shape are kneaded with the above-mentioned binder together with a molding method such as press molding, extrusion molding or casting.Molded body for skin material22 is made and thisMolded body for skin materialA molded body 23 is prepared in which 22 is arranged so as to cover the outer periphery of the core molded body 21 (see FIGS. 4B and 4C).
[0038]
  Next, using the extruder 100, the core material molded body 21 andMolded body for skin materialBy co-extrusion molding of the molded body 23 consisting of 22 around the core molded body 21Molded body for skin materialThe single-type composite fiber body 24 of FIG. 1 (a) coated with 22 and elongated to a thin diameter can be produced (see FIG. 4 (d)).
[0039]
  Then, using a mold 90 (lower punch: 90a and upper punch: 90b) that can be set parallel to the fiber direction of the composite fiber body 24 as shown in FIG. It is uniform by pressurizing in a state in which the upper punch 90b is fitted and pressed in an aligned state in the recessesFocused compact25 is obtained.
[0040]
  Further, as shown in FIG. 4 (f), a plurality of the coextruded long composite fiber bodies 24 are converged.Focused compact2 is coextruded again, so that the multi-type fiber with a high fiber density in FIG.Focused fiber molding26 can be made. In addition, the cross section of the composite fiber body 24 may be not only a circle but also a square or a triangle.
[0041]
  Further, according to the present invention, if the vibration is applied while heating before placing the upper punch 90b, the composite fiber body 24 becomes linear and has a more uniform structure.Focused compact25 can be obtained. At this time, it is desirable that the heating temperature is 80 to 200 ° C. and the frequency is 1 to 100 Hz in order to obtain a homogeneous structure by uniformly aligning the composite fiber bodies 24.
[0042]
  Next, as shown in FIG.Focused fiber molding26 is cut into a predetermined length of 0.1 mm to 10 mm, and then filled in a mold 28 or in a random state (FIG. 5 is an aligned arrangement) and heated and pressed.Collective molded bodyGet 27. In addition, thisCollective molded bodyIf necessary, as shown in FIG. 6, 27 may be passed between a pair of rollers 30 and rolled to produce a higher-density rolled composite compact 31.
[0043]
  And saidCollective molded body27,Rolled composite compact31 is heated or held at 300 to 700 ° C. for 10 to 200 hours to remove the binder, and then fired and integrated in a vacuum, air or inert atmosphere at a predetermined temperature and time for a composite structure The body 17 can be produced.
[0044]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example.
[0045]
  referenceExample 1
  70% by weight of alumina powder having an average particle size of 0.6 μm, 28% by weight of TiCN powder having an average particle size of 0.8 μm, and Yb having an average particle size of 0.5 μm₂O₃Co with 0.5% by weight of powder and average particle size of 0.5 μm₃O₄TiO with 0.5% by weight of powder and average particle size of 0.5 μm₂Mg with 0.5 wt% powder and average particle size of 0.5 μm₃N₄Powder is added at a ratio of 0.5% by weight in terms of MgO, and 100 parts by volume of ethylene ethyl acrylate, ethylene vinyl acetate, methoxy polyethylene glycol as an organic binder is added to the powder and kneaded to form a cylindrical shape. To form a core molded body.
[0046]
  On the other hand, 30% by weight of alumina powder having an average particle size of 0.6 μm, 68% by weight of TiCN powder having an average particle size of 0.8 μm, and Yb having an average particle size of 0.5 μm₂O₃Co with 0.5% by weight of powder and average particle size of 0.5 μm₃O₄TiO with 0.5% by weight of powder and average particle size of 0.5 μm₂Mg with 0.5 wt% powder and average particle size of 0.5 μm₃N₄Powder is added at a rate of 0.5% by weight in terms of MgO, and the same organic binder as above is added and kneaded to produce two half-cylindrical skin material moldings by extrusion molding. And arranged so as to cover the outer periphery of the core molding.CompactWas made.
[0047]
  And aboveCompactWas coextruded and stretched to a diameter of 1 mmComposite fiberAfter making this was distractedComposite fiberWhile 300 pieces are heated to 100 ° C using a mold 90, vibration of 10Hz is given with an amplitude of 2mm.,Thatrear,Obtained by heating to 140 ° C and press moldingRefocused compactCo-extrusion molding, multi-type with a diameter of 1mmFocused fiber moldingWas made.
[0048]
  Then this multi-typeFocused fiber moldingWas cut into 5 mm lengths, and the cut fibers were randomly filled into a carbon mold, and then molded in a state heated to 140 ° C. to obtain an aggregate molded body.
[0049]
  Then, after performing binder removal processing by heating up to 100-700 degreeC with respect to the said molded object in 70 hours, it heated up with the temperature increase rate of 10 degree-C / min, and was hot-pressed at 1700 degreeC for 1 hour. Fired,Composite structureWas made. In addition,Composite structureWhen the cross section of the core material was observed, the diameter of the core material was 20 μm, the maximum thickness d of the skin material aggregated portion / the average skin material thickness dm = 1.5, and no peeling or the like was observed between the core material and the skin material. It was.
[0050]
  And thisComposite structureWas processed into a cutting tool shape of RNGN120700 type, and further C-face processing and / or R honing processing was performed to produce a throw-away type cutting tool.
[0051]
The following conditions for the obtained throw-away chip
<Cutting conditions>
Work material: Inconel 718
Cutting speed 300m / min
Cutting depth: 1.5mm
Feed 0.2mm / rev
Condition: wet cutting
As a result of cutting test, a maximum of 0.33 mm of boundary wear occurred after cutting for 10 minutes, but no tool chipping occurred.
[0052]
Further, according to the IF method (JISR1607), the three-point bending strength was measured according to Hv, K1C, and JISR1601 at a load of 200N. As a result, Hv = 19 GPa, K1C = 7 MPam^1/2The bending strength was 850 MPa.
[0053]
  Example 1
  The core material of Reference Example 1 is made of Al having an average particle size of 0.3 μm.₂O₃ZrO with 85% by weight of powder and average particle size of 0.5μm₂14.6% by weight of powder, 0.15% by weight of NiO powder having an average particle size of 0.5 μm, Co having an average particle size of 0.8 μm₃O₄The raw material for the skin material of Example 1 is mixed with Si powder having an average particle size of 0.3 μm in a mixed powder having a ratio of 0.25% by weight of the powder.₃N₄Y with 88% by weight of powder and average particle size of 0.5 μm₂O₃Al with 9% by weight of powder and average particle size of 0.5μm₂O₃In the same manner as in Reference Example 1, except that the powder mixture was changed to a powder mixture of 3% by weight, the firing temperature was changed to 1500 ° C., and the average diameter Ds = 30 μm of the core material and the average thickness dm = 3 μm of the skin material were changed.Composite structureWas made. When measured from the cross-sectional photograph, the maximum thickness d of the skin material aggregated portion / the average skin material thickness dm = 1.3. As a result of performing a cutting test under the same conditions as in Reference Example 1, the maximum 0 after 10 minutes of cutting. .28 mm boundary wear occurred, but no tool chipping occurred. Also, Hv = 19.5 GPa, K_1C= 8 MPam^1/2Folding strength = 990 MPa.
[0054]
  Example 2
  The raw material for the skin material of Example 1 was composed of 88% by weight of SiC powder having an average particle size of 0.3 μm and Y having an average particle size of 0.5 μm.₂O₃Al with 9% by weight of powder and average particle size of 0.5μm₂O₃In the same manner as in Reference Example 1 except that the powder was changed to a mixed powder having a ratio of 3% by weight and the average diameter Ds of the core material was 40 μm and the average thickness dm of the skin material was 3 μm.Composite structureWas made. The maximum thickness d of the skin material agglomerated part / average skin material thickness dm = 1.4. As a result of performing a cutting test under the same conditions as in Reference Example 1, a maximum of 0.29 mm of boundary wear occurred after cutting for 10 minutes. No tool defects occurred. Also, Hv = 20 GPa, K_1C= 7 MPam^1/2The bending strength was 900 MPa.
[0055]
  Comparative Example 1
  referenceThe single type composite fiber body produced in Example 1 was used as it was and loaded into a mold to produce an aggregate molded body having a predetermined shape, thereby producing an RNGN120700 type cutting tool. At this time, the diameter of the core material was 300 μm, and the thickness of the skin material was 15 μm. As a result of performing the cutting test under the above conditions, the chipping occurred 4 minutes after the start of the cutting test and the cutting became impossible. Hv = 15 GPa, K_1C= 4 MPam^1/2Folding strength = 550 MPa.
[0056]
  Comparative Example 2
  After the composite sintered body of Reference Example 1 is filled with the composite fiber bodies 13 one by one in the extrusion molding apparatus 100 without using the mold of Reference Example 1, and then extruded., Aggregate molded bodyA cutting tool was produced in the same manner as in Reference Example 1 except that was prepared. At this time, the diameter of the core material was 30 μm, and there were 25 or more portions in the range of 100 μm × 100 μm where the maximum thickness of the skin material / average skin material thickness = 5. As a result of the cutting test under the above conditions, the chip was lost 6 minutes after the start of the cutting test.
[0057]
Hv = 15.5 GPa, K_1C= 4.5 MPa · m^1/2The bending strength was 500 MPa.
[0058]
  Example3
  100 parts by volume of a total amount of cellulose and polyethylene glycol as organic binder and polyvinyl alcohol as a solvent are added to diamond powder having an average particle size of 1.5 μm and mixed.TrainingThen, it was press-molded into a cylindrical shape with a diameter of 20 mm to produce a core body molded body.
[0059]
  On the other hand, 89% by weight of WC powder having an average particle diameter of 2.0 μm and 11% by mass of Co powder having an average particle diameter of 1.0 μm are mixed, and the same organic binder and solvent as above are added and kneaded. The thickness of the half cylinder shape is 1mmMolded body for skin materialAre formed by press molding, and these are arranged so as to cover the outer periphery of the core molded body.CompactWas made.
[0060]
  And aboveCompactWas coextruded and stretched to a diameter of 2 mmComposite fiberAfter making this was distractedComposite fiber100 using the mold 90 in the same manner as in Example 1.Focused compactAfter molding, multi-type with a diameter of 1mm by coextrusion moldingFocused fiber moldingWas made.
[0061]
  Next, the multifilament structureFocused fiber moldingAre cut into a length of 100 mm, aligned in parallel to form a sheet, and these three sheets are laminated so that the fiber directions are all in the same direction.Collective molded bodyWas made.
[0062]
  Then thisCollective molded bodyA back plate made of a sintered body of a cemented carbide with a thickness of 5 mm is disposed on the lower surface of the steel plate, and after removing the binder by raising the temperature from 300 to 700 ° C. in 100 hours, it is placed in an ultra high pressure apparatus. Then, it was fired under the conditions of 1450 ° C. × 15 minutes and 5 GPa to produce a cutting edge chip 3 in which the composite structure 4 and the back plate 5 were integrated. Then, this cutting edge tip 3 was processed and brazed at 700 ° C. using silver brazing to the mounting seat of the tool body 2 made of cemented carbide.
[0063]
Here, in the cutting tool 1 of the TNMG1604 type, the fiber direction L of the composite fiber body constituting the sheet_fAnd tangent L at the cutting edge ridge of cutting edge tip 3_cThe smallest angle α of each angle α_minWas 25 °, and the tip angle r was 60 °. Also, the fiber direction L at the apex P at the tip of the tip_fAnd tangent L at vertex P_cThe angle α formed by the above was 90 °.
[0064]
At this time, the average diameter Ds of the core material Ds = 30 μm, the average thickness d of the skin material_m= 1.5 μm, maximum thickness of skin material / average skin material thickness = 1.2.
[0065]
Using each cutting tool produced as described above,
Cutting depth d = 2mm,
Cutting speed V = 200 m / min,
Feed f = 0.2mm / rev
After cutting a plurality of workpieces (ADC14, with 4 grooves) and evaluating the number of workpieces until chipping or chipping occurred, chipping and chipping were found even after processing up to 2000 There wasn't.
[0066]
  Comparative Example 3
  Example3After producing a single filament structure composite fiber body having the same composition and structure as in Comparative Example 1,referenceExample in which each composite fiber body is inserted directly into the extruder without using the mold of Example 13A bundling composite fiber body was prepared in the same manner as in Example3A cutting tool was produced by brazing in the same arrangement as in Example 1, and evaluation was performed in the same manner. As a result, defects were observed when 1000 pieces were processed.
[0067]
【The invention's effect】
  As described above in detail, according to the method for manufacturing a composite structure of the present invention, when the composite fiber body is loaded again into the extrusion molding machine, the composite fiber body is aligned in a mold that can be set parallel to the fiber direction. By bundling a plurality of bundles in this state, a bundled compact is produced and loaded into the extruder to reduce the fiber diameter in the composite sintered body and to reduce the agglomerated part of the skin material. As a result, a composite structure excellent in fracture resistance and strength can be formed by taking advantage of the composite fiber body having excellent toughness and strength.
[Brief description of the drawings]
FIG. 1 shows a method for producing a composite structure according to the present invention.RuFor the shape, (a) a composite fiber body having a single filament structure, (b) a multifilament structureFocused fiber moldingIt is a perspective view which shows one embodiment of these.
FIG. 2 is a diagram of FIG.Focused fiber molded body (composite sintered body)FIG.
FIG. 3 of FIG.Focused fiber moldingGatheredCollective molded body (Composite structure)It is a schematic diagram which shows the example of an embodiment.
FIG. 4 shows a method for producing a composite structure according to the present invention.Composite fiberIt is process drawing for demonstrating this manufacturing method.
FIG. 5 is a schematic view showing a forming method step of an aggregate formed body for producing a composite structure in the method for manufacturing a composite structure of the present invention.
FIG. 6 is a schematic view showing another embodiment of a molding step of a collective molded body for producing a composite structure in the method for producing a composite structure of the present invention.
7 is a schematic diagram for explaining a configuration of a cutting tool using the composite structure of Example 3 and Comparative Example 3. FIG.
FIG. 8 shows a cutting tool using the composite structure of Example 3 and Comparative Example 3.Focused fiber molding (Composite fiber)It is a principal part enlarged top view for demonstrating arrangement | positioning.
FIG. 9 ConventionalFocused fiber molded body (composite sintered body)FIG.
[Explanation of symbols]
1 Cutting tool
2 Tool body
3 Cutting edge insert
4 Composite structure
5 Back plate
6 Cutting edge ridgeline
10 Composite sintered body(Bundled fiber molding)
11 Core
12 Skin material
13 Composite fiber
15 Skin material aggregation part
17, 18, 19, 20 Composite structure(Aggregate molded product)
21 Molded body for core material
22Molded body for skin material
23 Molded body
24 Composite fiber body (single filament structure)
25Focused compact
26Focused fiber molding(Multifilament structure)
27Collective molded body
28 Mold
30 Laura
31 Rolled composite compact

Claims (1)

(A) A step of producing a composite fiber body in which a skin material molded body having a composition different from that of the core material molded body is coated around the fibrous core material molded body by coextrusion molding; b) A plurality of the composite fiber bodies obtained by the step (a) are bundled in a state where the composite fiber bodies are aligned in a mold that can be set in parallel to the fiber direction, and the plurality of composite fiber bodies are 80 to A step of producing a converged molded body by applying vibration in a state heated to 200 ° C. to correct warpage of each composite fiber body and aligning them, and then pressing the converged composite fiber bodies by press molding. And (c) a step of producing a converged fiber molded body in which a plurality of the composite fiber bodies are converged and stretched by loading into the extrusion molding machine the extruded molded body obtained in the step (b) and performing extrusion molding. And (d) the bundled fiber molded body obtained in step (c). A step of producing an aggregate molded body in which a plurality of the aggregates are assembled and firing ;
Comprising
A first ceramic comprising at least one oxide, carbide, nitride and carbonitride selected from the group consisting of Group 4a, 5a and 6a group metals, aluminum and silicon in the periodic table;
Periodic Tables 4a, 5a and 6a Group 1st hard particles composed of one or more of carbides, nitrides and carbonitrides of 65a to 98% by mass and at least 1 selected from the group of iron, cobalt and nickel A first hard sintered body obtained by bonding seed bonding metals at 2 to 35 mass%,
A diamond sintered body obtained by bonding 60 to 99% by mass of diamond with a binding metal of 1 to 40% by mass of an iron group metal;
Alternatively, 20 to 99% by mass of cubic boron nitride is added to the periodic table 4a, 5a, 6a group metal and silicon, aluminum carbide, nitride, carbonitride, boronide and oxide, and one type of iron group metal. A cBN sintered body formed by bonding at 1 to 80% by mass of the binder composed of the above,
Composite sintering in which a plurality of composite fiber bodies each covered with a skin material having a composition different from that of the core material around a fibrous core material made of An area Ss of the skin material with respect to an area Sc of the core material in the composite sintered body, wherein the core material has a diameter of 5 to 50 μm, and is a composite structure having a structure in which a plurality of bodies are assembled. Ratio (Ss / Sc) is 30% or less, and in an arbitrary area of 100 μm × 100 μm in the composite sintered body, the thickness d is 3 or more in terms of the ratio (d / Ds) to the diameter Ds of the core material A composite structure having no skin material agglomerated portion and having a thickness d of the skin material agglomerated portion of 3 or less in terms of the ratio (d / dm) to the average thickness dm of the skin material is produced. Manufacturing method.

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