JP4676906B2 - Heat-resistant aluminum alloy for drawing - Google Patents

Description

  The present invention is used for applications that require high strength and high toughness in a high temperature range exceeding 100 ° C., as parts of aircraft and space equipment, structural materials, parts of internal combustion engines such as automobiles, turbochargers, etc. The present invention relates to a heat-resistant aluminum alloy for drawing.

  As a method for increasing the strength of an aluminum alloy material, an age hardening phenomenon has been widely used. However, in general, when such an aluminum alloy age hardened material is exposed to a high temperature range exceeding 100 ° C. for a long time, the softening is often caused by the coarsening of the age precipitate. Therefore, in order to suppress such softening, JIS A2618 alloy and A2219 alloy, which are Al-Cu based alloys, are generally used as heat-resistant alloys by adding various elements and optimizing component compositions to improve high temperature strength. It is put into practical use as an aluminum alloy.

  In order to further improve the high-temperature strength of such an Al—Cu alloy, it has been attempted to add Ag together with Mg as disclosed in, for example, Patent Document 1 and Patent Document 2.

  However, high-temperature characteristics (heat resistance and high-temperature proof stress) and toughness are generally difficult to achieve at the same time, and even the conventional technology proposed above has not improved both high-temperature characteristics and toughness at the same time. there were. That is, in the case of the proposed technique, the toughness value is sacrificed in order to improve the strength at high temperature, and therefore, the reliability is particularly low for members and structures subjected to high stress accompanied by fracture. I didn't get it.

  On the other hand, the present inventors have proposed a method for improving toughness at the same time as high temperature characteristics by adding Mg and Ag to an Al—Cu alloy and simultaneously adding Zn in Patent Document 3. According to the technique of Patent Document 3, it has become possible to obtain excellent high temperature characteristics and at the same time improve toughness to some extent, but it can still sufficiently meet the recent higher demand for high temperature materials. There was no situation.

JP 51-37018 A Japanese Patent Laid-Open No. 62-1112748 JP 2004-137558 A

  An object of the present invention is to provide a heat-resistant aluminum alloy for stretch processing that has eliminated the above-described problems of the prior art and has sufficiently high temperature characteristics and toughness.

In order to solve the above-mentioned problems, the present inventors have conducted various experiments and studies on an alloy in which Mg and Ag are added to an Al—Cu system, that is, an Al—Cu— Mg— Ag system alloy. Further, it has been found that high temperature strength and high toughness can be improved at the same time by simultaneously adding appropriate amounts of Ti and Mn, and in that case, the ratio of the addition amount of Ti and Mn (Mn / The present inventors have found that it is also necessary to set the Ti ratio within an appropriate range, and have reached the present invention. Furthermore, it is also effective to add V or Zn in addition to Ti and Mn. In that case, the ratio Mn / (Ti + V) ratio between the amount of Mn and the total amount of Ti and V is within an appropriate range. Has been found to be effective for obtaining high-temperature strength and high toughness.

Specifically, the heat-resistant aluminum alloy for extension work of the invention of claim 1 is Cu 5.1-6.5%, Mg 0.10-0.7%, Ag 0.10-1.0%, Mn 0.10. ~ 0.50%, Ti 0.22 ~ 0.50%, Mn / Ti ratio Mn / Ti is in the range of 0.5 ~ 2.5, the balance is Al and inevitable It is characterized by comprising an impurity.

Further, the heat-resistant aluminum alloy for stretch processing according to the invention of claim 2 is Cu 5.1 to 6.5%, Mg 0.10 to 0.7%, Ag 0.10 to 1.0%, Mn 0.10 to 0.50. %, Ti 0.06 to 0.50%, and V 0.02 to 0.25%, Zn 0.06 to 0.35%, or one or two of them, the balance being Al and inevitable Ri Na from impurities, yet the total amount of Ti and V (Ti + V) is not less 0.17% or more, and the ratio Mn / (Ti + V) of the total amount of Mn amount and Ti and V are 0.5 to 2.5 It is characterized by being within the range .

  The heat-resistant aluminum alloy for stretch processing according to the present invention can improve both the high-temperature strength and toughness, which are generally said to be difficult to achieve, compared to conventional alloys, and therefore, even in higher temperature and higher load environments. It can be suitably used without impairing reliability. In other words, the aluminum alloy for extension work of the present invention is used after being subjected to extension processes such as rolling, forging, and extrusion as parts and structural members that require high strength and high toughness in a high temperature range exceeding 100 ° C. For example, it can be suitably used for an outer wall of a high-speed moving body such as a rocket or an aircraft, an internal combustion engine or a supercharger member. Therefore, according to this invention, the outstanding effect that the use which can make use of the advantage of an aluminum alloy is expanded greatly can be produced.

The heat-resistant aluminum alloy for stretch processing of the present invention is basically an Al-Cu-Mg-Ag alloy obtained by adding Mg and Ag to an Al-Cu-based age 2000 heat-resistant alloy. A base is added , and Mn and Ti are further added at the same time.

  Here, in the Al—Cu—Mg—Ag based alloy which is the premise of the alloy of the present invention, an Al—Cu based so-called θ ′ phase or an Al—Cu—Mg—Ag based so-called Ω phase is precipitated by aging treatment. In addition, these aging precipitates contribute to the hardening, and it is possible to obtain high strength. In this invention, however, the aging precipitates can be further refined by simultaneously adding Mn and Ti in appropriate amounts. It is possible to suppress the coarsening of aging precipitates that occur when exposed to high temperatures for a long time (during high-temperature exposure), thereby improving toughness and further improving high-temperature strength. It becomes possible. The component composition of the heat-resistant aluminum alloy for stretch processing according to the present invention is also determined from the viewpoint of sufficiently exhibiting these actions and obtaining high high-temperature strength and excellent toughness. Therefore, the reason for limiting the component composition in the heat-resistant aluminum alloy of the present invention will be described below.

Cu:
By adding Cu, an Al—Cu-based θ ′ phase or an Al—Cu—Mg—Ag-based Ω phase is precipitated by aging treatment as described above, and contributes to curing. If the amount of Cu is less than 5.1%, the effect cannot be sufficiently obtained, and if it exceeds 6.5%, a stable phase θ that cannot be completely melted by the solution treatment is formed, leading to a decrease in toughness. Therefore, the amount of Cu is set within the range of 5.1 to 6.5%. In addition, when higher intensity | strength is required, it is desirable to make Cu amount into 5.3% or more.

Mg:
Mg also precipitates an Al—Cu—Mg—Ag Ω phase by aging treatment and contributes to hardening. If the amount of Mg is less than 0.10%, the effect cannot be sufficiently obtained. On the other hand, addition of Mg exceeding 0.7% cannot be expected to further improve the strength, but also decreases ductility and toughness. It becomes remarkable. Therefore, the amount of Mg is set within the range of 0.10 to 0.7%. In particular, when high strength is required, the Mg content is desirably 0.2% or more.

Ag:
Ag also contributes to hardening by precipitating an Ω phase by aging treatment. If the amount of Ag is less than 0.10%, the effect cannot be sufficiently obtained. On the other hand, even if Ag exceeds 1.0%, further improvement in strength cannot be expected, and the amount of expensive Ag used increases. It only reduces the economy. Therefore, the Ag content is set in the range of 0.10 to 1.0%. In particular, when high strength is required, the Ag content is desirably 0.2% or more.

Mn, Ti:
When Mn is added, the effect of refining the aging precipitates and the effect of suppressing the coarsening of the aging precipitates that occur during high temperature exposure are recognized. However, Mn is forcibly solidified at the outer periphery of the solidification cell during casting solidification and tends to concentrate, and since it diffuses slowly in the aluminum alloy, it can be used at high temperatures such as homogenization and solution treatment after casting. Even when heat treatment, rolling, extrusion, forging, and other spreading processes are performed, segregation of Mn cannot be completely eliminated. The suppression effect is limited to the Mn enriched region in the alloy structure.

  On the other hand, when Ti is added, as in the case of adding Mn, the effect of refining the aging precipitate and the effect of suppressing the coarsening of the aging precipitate that occurs during high temperature exposure are recognized. However, Ti is forced to dissolve in the center of the solidification cell during casting solidification and concentrates easily. In addition, since Ti diffuses slowly in the aluminum alloy, it can be used at high temperatures such as homogenization and solution treatment after casting. Ti segregation cannot be completely eliminated even by performing heat treatment, forging, extrusion, rolling, or other extension processing. Therefore, the effect of refining aging precipitates by addition of Ti and the effect of suppressing aging precipitate coarsening during high temperature exposure are limited to the Ti-enriched region in the alloy structure.

  Therefore, when only one of Mn and Ti is added alone, the precipitation state of aging precipitates in the alloy structure becomes non-uniform due to segregation of Mn or Ti, so that the strength and toughness are improved. It is difficult to achieve sufficient effects. On the other hand, if Mn and Ti are added at the same time, a microstructure in which Ti is concentrated in the Mn-diluted region and conversely Mn is concentrated in the Ti-diluted region is obtained. In this case, the aging precipitates become fine in each of the Mn enriched region and the Ti enriched region, and at the same time, coarsening of the aging precipitates during high temperature exposure is suppressed. As a result, the aging precipitation structure becomes fine and uniform as a whole, and the strength and toughness of the entire alloy are remarkably improved. That is, by simultaneously adding Mn and Ti, not only can the effect of refining the aging precipitates and the effect of suppressing the coarsening of the aging precipitates when exposed to high temperatures be obtained, but the uniformity of the entire structure can be improved. Therefore, the high temperature strength and toughness can be remarkably improved, and the present invention has such a function and effect as a basic principle.

  Here, if the amount of Mn added is less than 0.10%, the above effect is insufficient. On the other hand, if Mn is added in excess of 0.5%, a large amount of coarse Al-Mn compounds are formed. This is not preferable because it causes a decrease in toughness. Therefore, the amount of Mn added is in the range of 0.10 to 0.5%. In addition, the Mn addition amount is optimal within the range of 0.15 to 0.40% even within this range.

Moreover, even if the addition amount of Ti is less than 0.22% , the above effect is insufficient. On the other hand, if Ti is added in excess of 0.5%, a large amount of coarse Al-Ti compounds are easily formed during casting. This is not preferable because it causes a decrease in toughness. Therefore, the amount of Ti added is set in the range of 0.22 to 0.50%. As will be described later, in the case where V is added simultaneously with Ti, that is, in the case of the heat-resistant aluminum alloy for stretch processing of the invention of claim 2, the amount of Ti added is 0.06 to 0.50%. Within range.

  Conventionally, Ti, which is considered as a refining component in a general aluminum alloy, is used for the purpose of refining ingot crystal grains by simultaneously forming B to form a Ti-B-based compound. Yes. However, in order to improve strength and toughness, it is not necessary that B is present in the aluminum alloy together with Ti. Rather, if Ti is completely fixed as a Ti-B compound, the strength and toughness are improved. It will disappear. Moreover, since Ti-B compound particles act as precipitation nuclei for Al-Ti compounds, if a large amount of B is added, the forced solid solution amount of Ti is reduced, resulting in the effect of refinement of aging precipitates. In addition, the tendency to inhibit the effect of suppressing aging precipitate coarsening during high temperature exposure becomes strong. Therefore, in the case of the aluminum alloy of the present invention, it is desirable that B is not added at all, or even if B is added for the purpose of crystal grain refinement, the addition amount is set to a very small amount of 15 ppm or less.

  As described above, by simultaneously adding Mn and Ti within an appropriate addition amount range, the effect of refining aging precipitates and the effect of suppressing aging precipitate coarsening during high temperature exposure are sufficiently exhibited, and the structure Can be obtained and high toughness can be obtained, but by controlling the ratio of Mn addition amount and Ti addition amount (Mn / Ti ratio) within the range of 0.5 to 2.5, The uniformity of the structure can be further improved to improve the high temperature characteristics and toughness, which is defined in claim 2.

  That is, by regulating the Mn / Ti ratio within the range of 0.5 to 2.5, the effect of refining the aging precipitates and the effect of suppressing the aging precipitate coarsening during high temperature exposure are assured and uniform throughout the alloy. As a result, it is possible to further improve the high temperature characteristics and toughness. Here, when the Mn / Ti ratio is less than 0.5, the effect of refining the aging precipitates in the Ti-enriched region and the effect of suppressing the coarsening of aging precipitates at the time of high-temperature exposure are relative to those in the Mn-enriched region. Therefore, if the Mn / Ti ratio exceeds 2.5, the aging precipitates in the Mn-concentrated region become finer. The effect and the effect of suppressing aging precipitate coarsening when exposed to high temperatures are relatively stronger than those in the Ti-enriched region, so the uniformity of the structure of the entire material is disrupted and the strength and toughness levels are slightly degraded. To do.

  It is possible to obtain sufficient characteristics to achieve the object of the present invention even by the alloy component composition defined in claims 1 and 2 as described above. However, as described below, V or Zn The characteristics can be further improved by adding, which is defined in claims 3 and 4.

V:
V, like Ti, tends to concentrate at the center of the solidification cell during casting solidification, and its diffusion is slow. In addition, in the V-concentrated region, aging precipitates are finely precipitated, and the effect of suppressing aging precipitate coarsening is observed when exposed to high temperatures. Therefore, the strength and toughness can be further improved by adding V together with Ti. Here, if the addition amount of V is less than 0.02%, the above effect is insufficient. On the other hand, if the addition amount of V exceeds 0.25%, a coarse Al-V compound is formed during casting, This is not preferable because it causes a decrease in toughness. Therefore, the amount of V added is in the range of 0.02 to 0.25%. In addition, the preferable addition amount range of V is 0.05 to 0.15%. Further, V has the same effect as Ti. Therefore, when V is added simultaneously with Ti, the amount of Ti added can be lowered, and the total amount of addition of Ti and V (Ti + V) is 0.17% or more. And 0.19% or more is more preferable.

Further, the V addition amount is adjusted in the above range, and at the same time, the ratio of the Mn addition amount to the total addition amount of Ti and V, that is, the Mn / (Ti + V) ratio is controlled to the range of 0.5 to 2.5. Thus, it is possible to reliably improve the high temperature characteristics and toughness. The reason for defining the Mn / (Ti + V) ratio within the range of 0.5 to 2.5 is the same as the reason for the Mn / Ti ratio already described.

  That is, by regulating the Mn / (Ti + V) ratio within the range of 0.5 to 2.5, the effect of refining the aging precipitates and the effect of suppressing the aging precipitate coarsening during high temperature exposure are ensured over the entire alloy. And it can improve uniformly and can aim at the further improvement of a high temperature characteristic and toughness as a result. Here, when the Mn / (Ti + V) ratio is less than 0.5, the effect of refining the aging precipitates in the Ti and V concentration regions and the effect of suppressing the coarsening of the aging precipitates during high temperature exposure are compared with those in the Mn concentration region. Therefore, the uniformity of the structure as a whole material is lost, the strength and the toughness level are slightly deteriorated, and if the Mn / (Ti + V) ratio exceeds 2.5, conversely in the Mn concentration region The effect of refinement of aging precipitates and the effect of suppressing aging precipitate coarsening at high temperature exposure are relatively stronger than those in the Ti and V-enriched regions, so the uniformity of the structure of the entire material is lost. , Strength and toughness levels are slightly degraded.

Zn:
By adding Zn, the strength and ductility can be improved. Here, if the Zn content is less than 0.06% , a remarkable improvement in strength and ductility cannot be obtained. On the other hand, if it exceeds 0.35%, a decrease in corrosion resistance is observed, which is not preferable. However, the deterioration of the corrosion resistance due to the excessive addition of Zn is not so great, and there is no particular problem up to about 0.5% in a good use environment. Therefore, the addition amount of Zn is set in the range of 0.06 to 0.35%. In addition, the preferable range of the addition amount of Zn is 0.10 to 0.30%.

  In addition to the elements described above, basically, Al and unavoidable impurities may be used. However, the other elements other than the above-described component elements also have the toughness and high temperature of the aluminum alloy for extension work according to the present invention. Inclusion within the range that does not inhibit the properties and other properties is allowed.

  For example, Cr and Zr contribute to strength improvement by forming fine dispersed particles of Al—Cr and Al—Zr. The dispersed particles in this case are more stable than the above Cu-based compounds in the use temperature range (100 to 250 ° C.) of the parts and members which are the main applications in the present invention, and therefore can maintain high strength. It becomes possible. However, if the addition amount of Cr and Zr exceeds 0.10%, respectively, it becomes difficult to obtain sufficient strength after artificial aging treatment when the quenching speed after solution treatment is slow, and castability is reduced. This is not preferable because the frequency of occurrence of cracks due to the reduction increases. Therefore, Cr and Zr are each preferably 0.10% or less, and more preferably 0.07% or less.

  In addition, Si contained as an inevitable impurity in the aluminum ingot easily forms a crystallized substance together with other transition metals and the like, resulting in a decrease in ductility and toughness of the material. When the Si content exceeds 0.15%, a significant decrease in toughness occurs, which is not preferable. The allowable content of Si is largely related to the balance between the economic viewpoint based on the price of the raw metal and the required characteristics suitable for the application. On the other hand, Si has an effect of improving the strength of the aluminum alloy. Judging from these, it is desirable that the Si content is in the range of 0.05 to 0.15%.

  Further, similarly to Si, Fe contained as an inevitable impurity in an aluminum ingot easily forms a crystallized substance together with other transition metals and the like, resulting in a decrease in material ductility and toughness. If the Fe content exceeds 0.20%, the toughness is clearly lowered, which is not preferable. The allowable content of Fe is also largely related to the balance between the economic viewpoint based on the price of the raw metal and the required properties suitable for the application. On the other hand, Fe has the effect of improving the high-temperature properties, and from these, Therefore, it is desirable that the Fe content is in the range of 0.10 to 0.20%.

  Although the method for manufacturing the aluminum alloy for extending | stretching of this invention as mentioned above is not specifically limited, A preferable manufacturing method is demonstrated below.

  First, an ingot is produced by casting an aluminum alloy melt adjusted to be within the component range of the present invention. In addition, when a compound containing Ti, which is an essential component of the present invention, crystallizes in a large amount as an initial crystal during casting, the amount of solid solution Ti in the Al ground decreases, and the amount of Ti solid solution in the Ti concentration region (Ti concentration) ) Is reduced, and there is a possibility that the effect of refining the aging precipitates and the effect of suppressing the coarsening of the aging precipitates at the time of high temperature exposure cannot be obtained sufficiently. Therefore, in order to actively generate a Ti-enriched region, a casting method having a high cooling rate, such as a continuous casting method or a semi-continuous casting method, that is, a casting method having an average cooling rate during solidification of 0.1 ° C./min or more should be applied. Is preferred.

  The cast ingot is then homogenized. In addition, when cutting an ingot before a homogenization process as needed, there is a possibility that the ingot may break due to residual stress. Therefore, even if the ingot is subjected to heat treatment at a temperature of 300 ° C. to 450 ° C. for less than 20 hours to relieve the residual stress of the ingot and then cut, it does not affect the achievement of the object of the present invention. Here, the homogenization temperature is preferably 490 to 530 ° C. and less than 25 hours. If the homogenization temperature is less than 490 ° C., the homogenization of Cu, Mg, and Ag, which are the main alloy elements contributing to aging precipitation strengthening, is insufficient, and it is impossible to improve the strength. On the other hand, if the homogenization temperature exceeds 530 ° C., the possibility of burning increases. Further, if the homogenization treatment time is long, Mn and Ti that have been forcibly dissolved during the homogenization treatment start to precipitate as Al—Mn and Al—Ti compounds. The effect of minimizing the aging precipitates such as the θ ′ phase or the Ω phase of Mn and Ti, and the effect of suppressing the coarsening of the aging precipitates that occur during high-temperature exposure are that Mn and Ti are dissolved in Al. Therefore, if an Al-Mn-based or Al-Ti-based compound is deposited more than necessary during the homogenization process, the intended effect of the present invention is hardly obtained. Therefore, the homogenization treatment time is preferably less than 25 hours, more preferably less than 15 hours.

  The ingot after the homogenization treatment is drawn into an aluminum wrought material having a desired shape determined by the application. More specifically, as the expansion process, a rolling process is performed on the plate material, a forging process is performed on the forging material, and an extrusion process is performed on the shape material. The Al-Cu-Mg-Ag alloy that is the subject of the present invention is likely to generate microporosity during casting, and this microporosity is a starting point of fracture and impairs toughness. Become. In general, a large number of crystallized substances exist in the ingot structure at the boundary of the solidification cell. In this case, even if the individual crystallized substances are fine, the toughness is hindered if they are densely present. Therefore, it is necessary to destroy the dense state of crystallized substances. Furthermore, in order to ensure toughness, it is also important to refine the crystal grains of the final product to 500 μm or less. The crystal grains here include both equiaxed grains and flat grains, but the crystal grain size in the case of flat grains is defined as the length in the major axis direction. In order to improve the microstructure as described above, a drawing process such as rolling, extrusion, forging, or the like is essential. Although the microstructure is affected by the processing rate, in order to improve toughness, the rolling reduction is 50% or more in the case of rolling, the extrusion ratio is 2 or more in the case of extrusion, and the forging ratio is 2 in the case of forging. The above is preferable. Further, in the case of a forged product, it is more desirable that the forging direction is performed not only in one direction but in at least two different directions, and the forging ratio in each direction is 2 or more.

  The aluminum alloy material after such extension processing is further subjected to solution treatment and quenching treatment, and then subjected to high-temperature artificial aging treatment. In this solution treatment, the solution treatment is desirably performed in the range of 495 to 535 ° C. in order to make Cu, Mg, and Ag, which are alloy components that contribute to age hardening, dissolve as much as possible. However, as in the case of the above-mentioned homogenization treatment, if Ti or Mn that has been forcibly dissolved is precipitated as an Al-Ti-based or Al-Mn-based compound more than necessary during the solution treatment, the object of the present invention is achieved. Therefore, the solution treatment time is preferably less than 15 hours, more preferably less than 8 hours. In addition, in the quenching treatment, the quenching cooling rate in the temperature range of 280 to 480 ° C. is set to 10 ° C./min or more in order to suppress reprecipitation of Cu, Mg, and Ag as alloy components contributing to age hardening as much as possible. It is desirable to cool to a temperature of 60 ° C. or lower when high strength is required, and to a temperature of 75 ° C. or higher when residual stress is a problem. The artificial aging treatment is desirably performed at 160 to 200 ° C. for about 2 to 60 hours. If residual stress due to quenching is particularly problematic, it is more desirable to perform a so-called T8 treatment in which an artificial aging treatment is performed after cold working such as cold rolling, cold forging, and stretching after the quenching treatment. .

  Hereinafter, the present invention will be described in more detail based on examples. However, it goes without saying that the present invention is not limited to these examples.

Each aluminum alloy having chemical components indicated by alloy codes A to U in Tables 1 and 2 was melted and semi-continuously cast to obtain an ingot having a thickness of 80 mm, a width of 200 mm, and a length of 1500 mm. After chamfering both sides of this ingot by 5 mm on each side, it was homogenized at 520 ° C. for 8 hours, and then hot rolled at a starting temperature of 450 ° C. to a plate thickness of 5 mm, and then cold rolled. A rolled plate having a thickness of 2 mm was used. From these rolled sheets, a JIS-5 tensile test piece having a tensile direction perpendicular to the rolling direction was taken, and the tensile test piece was subjected to a solution treatment at 520 ° C. for 2 hours, hot water at about 80 ° C. Quenching was performed, followed by aging treatment at 190 ° C. for 5 hours to obtain a test material. In order to evaluate the mechanical properties of the specimen, a tensile test was performed at room temperature. Further, for the purpose of evaluating the high temperature characteristics, the specimen was exposed at 190 ° C. for 300 hours and then subjected to a tensile test at room temperature.

In addition, as evaluation criteria for heat resistance, considering the performance of the current heat-resistant aluminum alloy, for example, JIS A2519 alloy, which is considered to have high strength as a wrought material, the proof stress is 390 N / mm ² and the tensile strength is high. It was judged that the heat resistance strength was excellent when the strength was 440 N / mm ² or more, the proof stress was 300 N / mm ² and the tensile strength was 380 N / mm ² or more after high temperature exposure. The toughness was simply evaluated by the elongation at break obtained by a tensile test. As an evaluation standard of the toughness, it was judged that the case of elongation of 7.0% or more immediately after aging and 9.0% or more after high temperature exposure was excellent in toughness. Table 3 shows the tensile test results after aging treatment and after high-temperature exposure treatment (after holding at 190 ° C. for 300 hours).

合金Ａは請求項１に係る発明の本発明例、合金Ｂは請求項１で規定するＭｎ／Ｔｉ比の条件を外れる参考例、合金Ｃ〜Ｋは請求項２に係る発明の本発明例、合金Ｌ、Ｍは請求項２で規定するＭｎ／（Ｔｉ＋Ｖ）比の条件を外れる参考例、合金Ｎは請求項１に係る発明に対する比較例、合金Ｏ〜Ｕは請求項２に係る発明に対する比較例である。

Alloy A is the inventive example of the invention according to claim 1, alloy B is a reference example that deviates from the Mn / Ti ratio defined in claim 1, and alloys C to K are inventive examples of the invention according to claim 2 , Alloys L and M are reference examples that deviate from the Mn / (Ti + V) ratio defined in claim 2, alloy N is a comparative example for the invention according to claim 1, and alloys OU are comparisons with the invention for claim 2. It is an example.

As is apparent from Table 3, in the alloys N to U of comparative examples in which the alloy composition of Cu, Mg, Ag, Mn, and Ti is outside the scope of the invention according to claim 1 or claim 2 , the heat resistance strength and toughness are Even if either one was excellent, none had both characteristics. In particular, in the alloys N to P and U of the comparative examples where the alloy composition is outside the scope of the invention according to claim 1 for Mn and Ti, the toughness is remarkably reduced. On the other hand , it was found that the alloys A and C to K of the present invention obtained high strength and excellent toughness both after aging treatment and after high temperature exposure.

In addition, in the case of the reference example alloy B that deviates from the Mn / Ti ratio defined in claim 1 , after the aging treatment and after the high temperature exposure, the Mn / Ti ratio satisfies the condition of claim 1 than the invention example A. the strength of the slightly lowered, toughness slightly lower, also example L departing conditions Mn / Ti + V ratio defined in claim 2, in M, satisfying Mn / Ti + V ratio of claim 2 invention After aging treatment, the strength after high temperature exposure was slightly lower and the toughness was slightly lower than in Examples C to K.

Further, it was found that the alloys C to K , which are examples of the present invention according to claim 2 , have characteristics equal to or higher than those of the alloy A , which is an example of the present invention according to claim 1. For example, Cu, Mg, from the comparison between alloys A and alloy C of the added amount is closer composition of Ag, Cu, Mg, although elements of the Ag is an element which greatly affects the both strength, according to claim 2 It was found that the alloy C containing the selective component Zn was excellent in high temperature strength and toughness within the range. Further, Cu, Mg, from the comparison between alloys A and alloy D of the added amount is closer composition of Ag, Cu, Mg, although elements of the Ag is an element which greatly affects the both strength, according to claim 2 It was found that the alloy D containing the selective component V within the above range is superior in high-temperature strength and excellent in toughness.

Further, the addition amount of Mn and Ti in alloy E and the addition amount of Ti in alloys F to H are respectively lower than those of other alloys, but both alloys have high strength after aging treatment and after high temperature exposure. It was obtained and was found to be excellent in toughness. This indicates that by adding V and Zn added as selective components within the range described in claim 2 , high temperature strength and toughness equivalent to other alloys could be maintained. .

On the other hand, in Alloy I and Alloy J in which the amount of Cr or Zr added is larger than that of other alloys, a slight decrease in the strength in the aging state was observed. Further, the alloy K having a higher content of Fe and Si than other alloys was found to have a slight decrease in toughness.

Claims (2)

Cu5.1~6.5% (mass%, hereinafter the same), Mg0.10~0.7%, Ag0.10~1.0%, Mn0.10~0.50%, Ti 0.22 ~0. Excellent toughness, characterized in that it contains 50%, and the ratio Mn / Ti content Mn / Ti is in the range of 0.5 to 2.5, with the balance being Al and inevitable impurities Heat resistant aluminum alloy Contains Cu 5.1-6.5%, Mg 0.10-0.7%, Ag 0.10-1.0%, Mn 0.10-0.50%, Ti 0.06-0.50%, and V0 .02～0.25% comprises one or two of Zn 0.06 to 0.35%, Ti and if the balance Ri name of Al and unavoidable impurities, yet containing V with Ti The total amount of V (Ti + V) is 0.17% or more, and the ratio Mn / total amount of Ti and V is Mn / (Ti + V) in the range of 0.5 to 2.5. A heat-resistant aluminum alloy for stretch processing with excellent toughness.