JP3005354B2 - Heat treatment method of Al powder alloy - Google Patents
Heat treatment method of Al powder alloyInfo
- Publication number
- JP3005354B2 JP3005354B2 JP4022759A JP2275992A JP3005354B2 JP 3005354 B2 JP3005354 B2 JP 3005354B2 JP 4022759 A JP4022759 A JP 4022759A JP 2275992 A JP2275992 A JP 2275992A JP 3005354 B2 JP3005354 B2 JP 3005354B2
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- Japan
- Prior art keywords
- strength
- alloy
- powder
- temperature
- grain size
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- Powder Metallurgy (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、疲れ強さに優れバルブ
リフタ等のエンジンの動弁系部品として有用なＡｌ粉末
合金の熱処理方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for heat-treating an Al powder alloy which has excellent fatigue strength and is useful as a valve train component of an engine such as a valve lifter.
【０００２】[0002]
【従来の技術】近年、エンジン部品を従来のスチールに
代えて、アルミニウム合金を用いて作製し、軽量化して
燃費を向上する検討が盛んに行われている。特に、バル
ブリフタやバルブスプリングリテーナ等の動弁系部品を
軽量化することは、燃費向上の効果の大きいことから、
検討課題として注目されてきた。2. Description of the Related Art In recent years, studies have been actively conducted to produce engine parts by using an aluminum alloy instead of conventional steel to reduce the weight and improve fuel efficiency. In particular, reducing the weight of valve train parts, such as valve lifters and valve spring retainers, has a great effect on improving fuel economy.
It has been drawing attention as an issue to be considered.
【０００３】しかし、これら部品は高強度を必要とする
ことから、現在ではスチールが主として用いられてお
り、これら部品を軽量化するため、アルミニウム合金を
使用するには、まだ強度が不足する。However, since these parts require high strength, steel is mainly used at present, and the strength is still insufficient for using aluminum alloys to reduce the weight of these parts.
【０００４】[0004]
【発明が解決しようとする課題】そこで、上記従来技術
の問題点を解決する方法としてアルミニウム合金の合金
組成を検討することにより高強度化させる検討が盛んに
試みられているが、強度を向上させるために合金総量を
増しているため、靱性が低下し、鍛造等による成形が困
難であるという問題点を有している。Therefore, as a method of solving the above-mentioned problems of the prior art, studies for increasing the strength by examining the alloy composition of an aluminum alloy have been actively attempted. Therefore, since the total amount of the alloy is increased, there is a problem that the toughness is reduced and it is difficult to form by forging or the like.
【０００５】一方、溶体化処理後に時効処理（Ｔ６処
理）することにより、ＣｕＡｌ2あるいはＳ化合物（Ａ
ｌ2ＣｕＭｇ）等を析出させ高強度化したＡｌ−Ｃｕ−
Ｍｇ系合金が開発されている。On the other hand, by aging treatment (T6 treatment) after the solution treatment, CuAl 2 or S compound (A
(l 2 CuMg) etc. to make Al-Cu-
Mg-based alloys have been developed.
【０００６】しかしながら、このＡｌ−Ｃｕ−Ｍｇ系合
金でも、前記のエンジン部品に適用するには強度が不十
分である。そこで、溶体化処理温度を高くして合金元素
の固溶量を増加し高強度化を図るという手法が用いられ
る。ところが、この合金はＡｌ−Ｃｕ−Ｍｇの３元共晶
点以上に加熱すると、局部溶解し却って強度が低下する
と共に形状の保持が困難となるので、通常工業的には管
理上限最高温度で局部溶解温度−１０℃となるように熱
処理している。そのため、溶体化処理温度を高くして高
強度化をするには、これが限度となり充分な強度向上が
得られない。[0006] However, even this Al-Cu-Mg alloy has insufficient strength to be applied to the above-mentioned engine parts. Therefore, a method of increasing the solution treatment temperature to increase the solid solution amount of the alloy element to increase the strength is used. However, when this alloy is heated to a temperature higher than the ternary eutectic point of Al-Cu-Mg, the alloy locally melts, lowering the strength and making it difficult to maintain its shape. Heat treatment is performed so that the melting temperature becomes −10 ° C. Therefore, when the solution treatment temperature is increased to increase the strength, this is the limit, and sufficient strength cannot be obtained.
【０００７】本発明は従来のＡｌ−Ｃｕ−Ｍｇ系合金が
溶体化処理温度を高くできず、そのため高強度化に限度
があるという前記のごとき問題点を解決するためになさ
れたものであって、溶体化処理温度をさらに高温化しバ
ルブリフタやバルブスプリングリテーナ等の動弁系部品
として実用化できる程度に高強度のＡｌ合金を得ること
ができるＡｌ粉末合金の熱処理方法を提供することを目
的とする。The present invention has been made in order to solve the above-mentioned problem that the conventional Al-Cu-Mg-based alloy cannot increase the solution treatment temperature and therefore has a limitation in increasing the strength. It is another object of the present invention to provide a method for heat-treating an Al powder alloy capable of further raising the solution heat treatment temperature to obtain an Al alloy having a strength high enough to be practically used as a valve train component such as a valve lifter or a valve spring retainer. .
【０００８】[0008]
【課題を解決するための手段】発明者等は、Ａｌ−Ｃｕ
−Ｍｇ系合金の溶体化処理時に、局部溶解により生成し
た液相が、粒界に集合し凝固時に脆い金属間化合物を生
成し、強度を低下することに鑑み、結晶粒径を細かくす
れば、前記の問題点を解決できるのではないかという着
想の下に、結晶粒微細化に有利なＡｌ粉末合金を用い、
結晶粒径との関連について鋭意研究を重ねた。Means for Solving the Problems The present inventors have proposed Al-Cu
-During the solution treatment of the Mg-based alloy, the liquid phase generated by local melting is aggregated at the grain boundary to generate a brittle intermetallic compound at the time of solidification, and in view of reducing the strength, if the crystal grain size is reduced, Under the idea that the above problems could be solved, using an Al powder alloy that is advantageous for grain refinement,
Intensive research was conducted on the relationship with the crystal grain size.
【０００９】その結果、塑性加工等により結晶粒径を制
御したとき、結晶粒径をある一定大きさ以下に微細化す
ると液相生成の影響を少なくして溶体化処理温度の上昇
が可能であり、これにより時効硬化後の強度を向上でき
ることを新たに知見して本発明を完成した。As a result, when the crystal grain size is controlled by plastic working or the like, if the crystal grain size is reduced to a certain size or less, the influence of liquid phase formation is reduced and the solution treatment temperature can be increased. The present inventors have newly found that this can improve the strength after age hardening, and completed the present invention.
【００１０】本発明のＡｌ粉末合金の熱処理方法は、結
晶粒径が０．３ｍｍ以下の析出硬化型熱処理用Ａｌ−Ｃ
ｕ−Ｍｇ系Ａｌ粉末合金を、局部溶解温度の±５℃の範
囲で溶体化処理を施し、その後時効硬化を行うことを要
旨とする。The heat treatment method for an Al powder alloy according to the present invention is a precipitation hardening type heat treatment Al-C alloy having a crystal grain size of 0.3 mm or less.
The gist of the present invention is to subject the u-Mg-based Al powder alloy to a solution treatment within a range of a local melting temperature of ± 5 ° C, and then to perform age hardening.
【００１１】[0011]
【発明の具体例の説明】以下に、本発明のＡｌ粉末合金
の熱処理方法をさらに具体的にした発明（具体例）につ
いて説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the invention (concrete example) in which the heat treatment method for an Al powder alloy of the present invention is more specifically described.
【００１２】本発明が適用されるＡｌ粉末合金は、析出
硬化型の熱処理Ａｌ−Ｃｕ−Ｍｇ系Ａｌ粉末合金であ
る。この合金の原料粉末はガスアトマイズ法、水アトマ
イズ法、回転アトマイズ法等のアトマイズ法によるもの
の他、ロール急冷法、メルトスピニング法等いずれの方
法で製造されるものでもよい。該粉末には急冷凝固粉末
を用いることが好ましく、原料粉末の粒径は３００μｍ
以下とすることが好ましい。原料粉末の大きさが３００
μｍを越えると、粉末の冷却速度が遅いため結晶粒や析
出相が粗大化し強度が低下するからである。The Al powder alloy to which the present invention is applied is a precipitation hardening type heat-treated Al-Cu-Mg-based Al powder alloy. The raw material powder of this alloy may be produced by any method such as a roll quenching method and a melt spinning method, in addition to an atomizing method such as a gas atomizing method, a water atomizing method and a rotary atomizing method. It is preferable to use a rapidly solidified powder as the powder, and the particle size of the raw material powder is 300 μm.
It is preferable to set the following. Material powder size is 300
If it exceeds μm, the cooling rate of the powder is low, so that the crystal grains and the precipitated phase are coarsened and the strength is reduced.
【００１３】Ａｌ合金粉末の表面は厚さ１００Å程度の
アルミニウム酸化物で覆われておりこの酸化物がバリヤ
となって焼結に際してアルミニウムやその他添加元素の
拡散を阻むため、焼結が進行しない。そこで、一般には
固化時に、物理的に粉末表面の酸化膜を破壊するため、
粉末を熱間押出やホットプレスで塑性変形させて拡散が
可能とした状態で接合する。The surface of the Al alloy powder is covered with aluminum oxide having a thickness of about 100 °, and this oxide acts as a barrier to prevent diffusion of aluminum and other additional elements during sintering, so that sintering does not proceed. Therefore, in general, during solidification, the oxide film on the powder surface is physically destroyed,
The powder is plastically deformed by hot extrusion or hot pressing and joined in a state where diffusion is possible.
【００１４】また、Ａｌ合金粉末の表面には酸化物の他
に水酸化物や吸着した水分、酸素等が存在しており、こ
のまま固化すると残留気孔となり材料特性を劣化させる
と共にふくれを発生させるので、粉末固化に相前後して
脱ガスが行われる。脱ガスは缶真空脱ガス法が最も一般
的であり、これには排気管を取り付けた金属の缶が用い
られる。一般にはプレスした圧粉体をこの金属缶の中に
挿入し、所定温度まで上げて排気しながら脱ガスする。
脱ガス後排気管を密封し、缶ごと熱間プレスする。次い
で、缶の部分を切削加工により除去してから、押出し、
圧延等により加工を行う。In addition, hydroxides, adsorbed moisture, oxygen, etc., as well as oxides, are present on the surface of the Al alloy powder. If solidified as it is, it becomes residual pores, deteriorating the material properties and causing blisters. Degassing is performed immediately before and after the solidification of the powder. The most common method of degassing is a can vacuum degassing method, in which a metal can fitted with an exhaust pipe is used. Generally, the pressed green compact is inserted into the metal can, heated to a predetermined temperature, and degassed while evacuating.
After degassing, the exhaust pipe is sealed and hot-pressed together with the can. Then, after removing the can portion by cutting, extrusion,
Processing is performed by rolling or the like.
【００１５】ここで結晶粒径が０．３ｍｍ以下の析出硬
化型熱処理用Ａｌ−Ｃｕ−Ｍｇ系Ａｌ粉末合金を準備す
る方法としては、具体的には、（１）上記のようにして
得られた析出硬化型熱処理用Ａｌ−Ｃｕ−Ｍｇ系粉末合
金に塑性加工を施し、該Ａｌ粉末合金の結晶粒径を微細
化して０．３ｍｍ以下とする方法、（２）上記Ａｌ粉末
合金そのものを作製する場合の切削等の加工処理におい
て、前記結晶粒径を０．３ｍｍ以下とする方法、（３）
Ａｌ合金粉末をＮｅａｒ Ｎｅｔ Ｓｈａｐｅに熱間鍛
造を施して固化する方法等が挙げられる。Here, the method of preparing an Al—Cu—Mg-based Al powder alloy for precipitation hardening type heat treatment having a crystal grain size of 0.3 mm or less is specifically (1) obtained as described above. A method of subjecting the precipitation-hardening type heat treatment Al-Cu-Mg powder alloy to plastic working to reduce the crystal grain size of the Al powder alloy to 0.3 mm or less; (2) producing the Al powder alloy itself (3) a method of reducing the crystal grain size to 0.3 mm or less in a processing such as cutting when performing
A method of subjecting the Al alloy powder to near net shape by hot forging and solidifying the powder is used.
【００１６】このとき、例えば塑性加工により結晶粒径
が制御できるのは、塑性加工量が増加するにつれて、格
子歪量が増加するが、格子歪量があるレベルより高くな
ると、溶体化温度に加熱した時に再結晶を起こす。この
時、格子歪量に応じて、再結晶核の生成頻度が増加する
ため、再結晶粒径を小さくできることによる。すなわ
ち、塑性加工量を制御することにより、結晶粒径が制御
できる。塑性加工による加工率と結晶粒径との関係は、
一例を示すと図２に示す通りであって、この場合結晶粒
径が０．３ｍｍ以下になるようにするためには、３％以
下の塑性加工あるいは２０％以上の塑性加工が必要であ
る。At this time, for example, the crystal grain size can be controlled by plastic working because the amount of lattice strain increases as the amount of plastic working increases, but when the amount of lattice strain becomes higher than a certain level, heating to a solution temperature is performed. When recrystallization occurs. At this time, the frequency of generation of recrystallization nuclei increases according to the amount of lattice strain, so that the recrystallized grain size can be reduced. That is, by controlling the amount of plastic working, the crystal grain size can be controlled. The relationship between the processing rate by plastic working and the crystal grain size is
An example is as shown in FIG. 2. In this case, plastic working of 3% or less or plastic working of 20% or more is required to make the crystal grain size 0.3 mm or less.
【００１７】なお、Ａｌ粉末合金が、重量比で、Ｃｕ；
２．５〜５．５％、Ｍｇ；０．３〜２．５％、Ｓｉ；
０．１０〜０．１９％、ＭｎとＣｒの１種または２種；
０．３〜１．０％を含み、残部が実質的にＡｌからなる
組成を有する合金であることが好ましい。該粉末合金を
用いることにより、熱処理後の疲労強度をより一層向上
させることができる。Incidentally, the Al powder alloy is composed of Cu;
2.5-5.5%, Mg; 0.3-2.5%, Si;
0.10 to 0.19%, one or two of Mn and Cr;
It is preferable that the alloy contains 0.3 to 1.0%, with the balance being substantially composed of Al. By using the powder alloy, the fatigue strength after the heat treatment can be further improved.
【００１８】ここで、上記好適なＡｌ粉末合金の元素添
加理由と組成範囲限定理由について説明する。 Ｃｕ；２．５〜５．５％ ＣｕはＡｌに固溶してその強度を向上させる元素であ
り、Ｍｇと共存してＡｌ−Ｃｕ−Ｍｇ系析出中間相
（Ｓ’相）を形成し、室温および高温強度を向上させ
る。その量が２．５％未満では前記効果が小さく、５．
５％を越えるとＳ’相が増加するため靱性が低下する。Here, the reasons for adding elements and the reasons for limiting the composition range of the above-mentioned preferable Al powder alloy will be described. Cu: 2.5 to 5.5% Cu is an element that forms a solid solution in Al to improve its strength, and forms an Al—Cu—Mg-based precipitation intermediate phase (S ′ phase) in the presence of Mg. Improves room and high temperature strength. If the amount is less than 2.5%, the effect is small,
If it exceeds 5%, the S 'phase increases and the toughness decreases.
【００１９】Ｍｇ；０．３〜２．５％ ＭｇはＡｌに固溶してその強度を向上させる元素であ
り、Ｃｕと共存してＡｌ−Ｃｕ−Ｍｇ系析出中間相
（Ｓ’相）を形成し、室温および高温強度を向上させ
る。その量が０．３％未満では前記効果が小さく、２．
５％を越えるとＳ’相が増加するため靱性が低下する。Mg: 0.3 to 2.5% Mg is an element that forms a solid solution in Al to improve its strength, and coexists with Cu to form an Al—Cu—Mg-based precipitation intermediate phase (S ′ phase). Form and improve room temperature and high temperature strength. If the amount is less than 0.3%, the effect is small.
If it exceeds 5%, the S 'phase increases and the toughness decreases.
【００２０】Ｓｉ；０．１０〜０．１９％ ＳｉはＡｌ−Ｃｕ−Ｍｇ３元系に添加されてＭｇ2Ｓｉ
を析出して強化すると共に、Ｓ’相を微細に形成させ
て、室温および高温強度を向上する。０．１０％未満で
は前記効果が認められず、０．１９％を越えると一部の
Ｓｉが粒界上に析出するため、靱性が低下する。Si: 0.10 to 0.19% Si is added to the Al-Cu-Mg ternary system to form Mg 2 Si.
Is precipitated and strengthened, and the S ′ phase is finely formed to improve the room temperature and high temperature strength. If it is less than 0.10%, the above effect is not observed. If it exceeds 0.19%, a part of Si precipitates on the grain boundaries, and the toughness is reduced.
【００２１】Ｍｎ、Ｃｒ；０．３〜１．０％ ＭｎおよびＣｒはＳｉと共存して再結晶組織を微細にす
る。この結果、熱処理材における室温および高温強度を
向上させ、同時に延性および靱性も向上する。延性およ
び靱性向上の効果は、０．５〜０．６％の時に最も強く
現れ、０．３％未満でも１．０％を越えても、その効果
は不十分である。さらに、０．３％未満では強度の向上
が認められない。Mn, Cr: 0.3 to 1.0% Mn and Cr coexist with Si to make the recrystallized structure fine. As a result, the room temperature and high temperature strength of the heat-treated material is improved, and at the same time, the ductility and toughness are also improved. The effect of improving ductility and toughness is most pronounced when the content is 0.5% to 0.6%, and the effect is insufficient even if less than 0.3% or more than 1.0%. Further, if less than 0.3%, no improvement in strength is observed.
【００２２】[0022]
【作用】溶体化温度を上昇させ局部溶解温度以上に加熱
すると、生成した液相は粒界に集合し凝固時に粒界に脆
い金属間化合物を生成し強度を低下させると共に、液相
生成量が多い場合には溶体化後の焼入れ時に割れ等が発
生する。しかし、本発明のＡｌ粉末合金の熱処理方法
は、Ａｌ−Ｃｕ−Ｍｇ系合金粉末を粉末冶金法により粉
末固化し、塑性加工等により結晶粒径を０．３ｍｍ以下
としたので、粒界面積が大きく前記の液相の影響が少な
く、局部溶解温度以上に加熱しても強度低下が小さく、
さらに焼割れが発生することもない。[Function] When the solution temperature is raised to a value higher than the local melting temperature, the generated liquid phase aggregates at the grain boundaries and forms a brittle intermetallic compound at the grain boundaries during solidification, lowering the strength and reducing the amount of liquid phase generated. If the amount is large, cracks or the like occur during quenching after solution treatment. However, in the heat treatment method for Al powder alloys of the present invention, the Al-Cu-Mg alloy powder is solidified by powder metallurgy and the crystal grain size is reduced to 0.3 mm or less by plastic working or the like. Largely less affected by the liquid phase, even when heated above the local melting temperature, the strength drop is small,
Further, no cracking occurs.
【００２３】そのため、溶体化温度を局部溶解温度の±
５℃まで上昇することができるので、Ｃｕ、Ｍｇあるい
はＳｉ等の添加元素の固溶量を増大させることができ、
その後の時効硬化処理により、Ｓ’相（Ａｌ2ＣｕＭ
ｇ）やθ相（ＣｕＡｌ2）の形成により強度が向上し、
バルブリフタやバルブスプリングリテーナ等の動弁系部
品として実用化できる程度に高強度のＡｌ合金を得るこ
とができる。Therefore, the solution temperature is set to ± the local melting temperature.
Since the temperature can be increased up to 5 ° C., the solid solution amount of an additional element such as Cu, Mg or Si can be increased,
After the age hardening treatment, the S ′ phase (Al 2 CuM
g) and the formation of the θ phase (CuAl 2 ) improve the strength,
It is possible to obtain an Al alloy having high strength enough to be practically used as a valve train system component such as a valve lifter or a valve spring retainer.
【００２４】本発明において、Ａｌ粉末合金の結晶粒径
を０．３ｍｍ以下としたのは、結晶粒径が０．３ｍｍを
越えると、局部溶解温度以上に加熱した時に生成した液
相が粒界に集合し凝固時に粒界に脆い金属間化合物を生
成し強度を低下させると共に、液相生成量が多い場合に
は溶体化後の焼入れ時に割れ等が発生するからである。In the present invention, the crystal grain size of the Al powder alloy is set to 0.3 mm or less because, when the crystal grain size exceeds 0.3 mm, the liquid phase generated when heated to a temperature higher than the local melting temperature becomes a grain boundary. This is because they form a brittle intermetallic compound at the grain boundaries during solidification and reduce the strength, and when a large amount of liquid phase is formed, cracks and the like occur during quenching after solution treatment.
【００２５】溶体化温度を局部溶解温度の±５℃とした
のは、局部溶解温度−５℃未満では、合金元素を充分に
固溶することができず、所望の強度の向上が得られない
からであり、局部溶解温度＋５℃を越えると、液相の生
成の影響が増大し強度が低下し焼割れが発生するからで
ある。The reason for setting the solution temperature to ± 5 ° C. of the local melting temperature is that if the local melting temperature is lower than −5 ° C., the alloy element cannot be sufficiently dissolved to obtain a desired strength. If the temperature exceeds the local melting temperature + 5 ° C., the influence of the formation of a liquid phase increases, the strength decreases, and burning cracks occur.
【００２６】図１は本発明のＡｌ粉末合金（Ｐ／Ｍ材）
と従来のＡｌインゴット合金（Ｉ／Ｍ材）の溶体化温度
と強度（疲労強度）の関係を示す線図である。溶体化温
度が高くなるとＰ／Ｍ材もＩ／Ｍ材も共に強度が高くな
っているが、Ｉ／Ｍ材および粒径の大きなＰ／Ｍ合金の
場合は局部溶解温度（Ｔ0）以上の温度では強度が急激
に低下している。これは、Ｔ0以上の温度では、局部溶
解により液相が生成するためである。FIG. 1 shows an Al powder alloy (P / M material) of the present invention.
FIG. 4 is a diagram showing a relationship between solution heat temperature and strength (fatigue strength) of a conventional Al ingot alloy (I / M material). The higher the solution temperature, the higher the strength of both the P / M material and the I / M material. However, in the case of the I / M material and the P / M alloy having a large grain size, the strength is higher than the local melting temperature (T 0 ). At temperature, the strength drops sharply. This is because at a temperature equal to or higher than T 0 , a liquid phase is generated by local melting.
【００２７】一方、粒径を０．３ｍｍ以下に制御したＰ
／Ｍ材はＴ0＋５℃で強度が最大となりＴ0＋５℃を越え
るとＩ／Ｍ材と同様に強度が急激に低下する。これは前
述のように粒界面積が大きいため液相の影響が小さくな
り、Ｔ0にて液相が発生するが溶体化温度が高いことに
よる固溶量増大による高強度化の効果の方が大きいた
め、Ｔ0を越えても強度が向上するからである。また、
Ｔ0＋５℃を越えると液相発生の影響の方が大きくな
り、強度が低下する。On the other hand, when the particle diameter is controlled to 0.3 mm or less,
The / M material has the maximum strength at T 0 + 5 ° C., and when the temperature exceeds T 0 + 5 ° C., the strength sharply decreases like the I / M material. This is because the influence of the liquid phase is reduced due to the large grain boundary area as described above, and a liquid phase is generated at T 0 , but the effect of increasing the strength by increasing the amount of solid solution due to the high solution temperature is better. This is because the strength is improved even if T 0 is exceeded. Also,
If the temperature exceeds T 0 + 5 ° C., the influence of the generation of a liquid phase is greater, and the strength is reduced.
【００２８】[0028]
【実施例】本発明の実施例を比較例と対比しつつ説明
し、本発明の効果を明らかにする。表１に示す化学成分
のＡｌ合金を粉末冶金法（Ｐ／Ｍ）または溶製法（Ｉ／
Ｍ）にて製造した。なお、Ｉ／Ｍ材には、φ２０ｍｍの
押出棒を用い、Ｐ／Ｍ材は下記に示す方法にて製造し
た。EXAMPLES Examples of the present invention will be described in comparison with comparative examples to clarify the effects of the present invention. An Al alloy having the chemical composition shown in Table 1 was prepared by powder metallurgy (P / M) or smelting (I /
M). In addition, the extrusion rod of 20 mm was used for the I / M material, and the P / M material was manufactured by the following method.
【００２９】Ｐ／Ｍ材は、空気噴霧により表１に示す化
学成分のアルミニウム合金粉末を製造し、３００μｍ以
下に分級した。この合金粉末を外径２．５インチのアル
ミニウム缶に挿入した後、缶内の空気および粉末表面に
吸着している水分を取り除くため、４８０℃にて１時間
の真空脱ガス処理を施し、これを押出用ビレットとし
た。このビレットを４００℃にて押出比１５で直径１８
ｍｍの丸棒とした。As for the P / M material, an aluminum alloy powder having the chemical components shown in Table 1 was produced by air spraying, and classified to 300 μm or less. After inserting the alloy powder into an aluminum can having an outer diameter of 2.5 inches, vacuum degassing is performed at 480 ° C. for 1 hour to remove air and moisture adsorbed on the powder surface in the can. Was used as a billet for extrusion. The billet is extruded at 400 ° C. at an extrusion ratio of 15 and a diameter of 18
mm round bar.
【００３０】さらにＰ／Ｍ材に、所定の加工率で塑性加
工し、結晶粒径を表１に示す通りとした。なお、結晶粒
径は次式により求めた。 ｄ＝（１／Ｍ）×（Ａ／ｎ）1/2 ｎ＝Ｚ＋（Ｗ／２） ｄ：結晶粒径（ｍｍ） Ａ：測定断面積（ｍｍ
2） Ｗ：周辺部の結晶粒数 Ｍ：測定倍率 ｎ：全結晶粒数 Ｚ：測定断面積Ａ内に完全に含まれる結晶粒数Further, the P / M material was plastically processed at a predetermined processing rate, and the crystal grain size was as shown in Table 1. The crystal grain size was determined by the following equation. d = (1 / M) × (A / n) 1/2 n = Z + (W / 2) d: grain size (mm) A: measured cross-sectional area (mm)
2 ) W: Number of crystal grains in peripheral part M: Measurement magnification n: Total number of crystal grains Z: Number of crystal grains completely included in measured cross-sectional area A
【００３１】続いて、これら材料を表１に示す溶体化温
度にて１時間保持後水冷して溶体化処理を施し、直ちに
１８５℃にて８時間時効処理を施した。なお、表１の各
材料の局部溶解温度Ｔ0示差熱分析により測定したとこ
ろ、５０６〜５０８℃であった。Subsequently, these materials were maintained at a solution temperature shown in Table 1 for 1 hour, then cooled with water, subjected to a solution treatment, and immediately subjected to an aging treatment at 185 ° C. for 8 hours. Incidentally, it was measured by the local melting temperature T 0 differential thermal analysis of each material in Table 1, was 506-508 ° C..
【００３２】次いで、これら材料から疲労試験片を作製
し疲労強度を測定しその結果を表１に示した。なお、疲
労試験は室温にて回転曲げ疲労試験により実施した。Next, fatigue test pieces were prepared from these materials, and the fatigue strength was measured. The results are shown in Table 1. The fatigue test was performed at room temperature by a rotary bending fatigue test.
【００３３】[0033]
【表１】 [Table 1]
【００３４】表１に示したように、比較例１、８、９は
溶体化温度が４７０℃と低かったため、合金元素の固溶
化が充分でなく、疲労強度はそれぞれ１６５、１６６、
１６１ＭＰａと低かった。逆に比較例２および７は溶体
化温度がＴ0＋５℃より高い５２０℃であったため、疲
労強度が１８３ＭＰａおよび１８１ＭＰａに低下した。
比較例３は結晶粒径が０．５ｍｍと大きく、しかもＴ0
温度以上に加熱されたため、液相の発生により溶体化時
に割れを発生した。比較例１０は結晶粒径が０．５２ｍ
ｍと大きいために疲労強度は低い。比較例１１は結晶粒
度が０．５１ｍｍと大きくしかもＴ0温度以上に加熱さ
れたために疲労強度は１９９ＭＰａに低下した。As shown in Table 1, in Comparative Examples 1, 8, and 9, the solution temperature was as low as 470 ° C., so that the solution of the alloying elements was not sufficient, and the fatigue strength was 165, 166, respectively.
It was as low as 161 MPa. Conversely, in Comparative Examples 2 and 7, since the solution temperature was 520 ° C. higher than T 0 + 5 ° C., the fatigue strength was reduced to 183 MPa and 181 MPa.
Comparative Example 3 had a crystal grain size as large as 0.5 mm and T 0
Since it was heated to a temperature higher than the temperature, a crack was generated during solutionizing due to generation of a liquid phase. Comparative Example 10 has a crystal grain size of 0.52 m.
The fatigue strength is low due to the large m. In Comparative Example 11, the fatigue strength was reduced to 199 MPa because the crystal grain size was as large as 0.51 mm and heated to a temperature of T 0 or more.
【００３５】比較例４〜６は溶製材であって、結晶粒径
も０．８ｍｍと大きく、Ｔ0温度以下１０℃に加熱され
て、強度の最も高かった比較例５でも、その疲労強度が
１９２ＭＰａであったが、Ｔ0温度以上に加熱された比
較例４は液相発生の影響を受けて、疲労強度が１５２Ｍ
Ｐａに低下し、溶体化温度の低過ぎた比較例６は、添加
元素の固溶量が低かったので、疲労強度は１７１ＭＰａ
と低かった。Comparative Examples 4 to 6 are ingots having a large crystal grain size of 0.8 mm, and were heated to 10 ° C. below the T 0 temperature. Although it was 192 MPa, Comparative Example 4 heated to a temperature of T 0 or more was affected by the generation of the liquid phase, and had a fatigue strength of 152M.
In Comparative Example 6 in which the solution solution temperature was too low and the solid solution amount of the added element was low, the fatigue strength was 171 MPa.
Was low.
【００３６】これに対して本発明の実施例１〜８は、溶
体化後の時効処理により充分な強度を発揮する元素を必
要量含有する粉末合金を用い、結晶粒径を０．３ｍｍ以
下に微細化したので、Ｔ0±５℃で溶体化することによ
り、発生する液相の影響を少なくして固溶量増大による
高強度化の効果を得ることが出来たため、その後の時効
処理により疲労強度は２１５〜２２７ＭＰａと著しく向
上することが判明し、本発明の効果を確認することがで
きた。On the other hand, in Examples 1 to 8 of the present invention, a powder alloy containing a necessary amount of an element exhibiting sufficient strength by aging treatment after solution treatment was used, and the crystal grain size was reduced to 0.3 mm or less. Since the solution was refined, it was possible to reduce the influence of the liquid phase generated by forming a solution at T 0 ± 5 ° C and obtain the effect of increasing the strength of the solid solution by increasing the amount of solid solution. The strength was found to be remarkably improved to 215 to 227 MPa, and the effect of the present invention could be confirmed.
【００３７】[0037]
【発明の効果】本発明のＡｌ粉末合金の熱処理方法は以
上説明したように、結晶粒径が０．３ｍｍ以下である析
出硬化型熱処理用Ａｌ−Ｃｕ−Ｍｇ系Ａｌ粉末合金を、
局部溶解温度の±５℃の範囲で溶体化処理を施し、その
後時効硬化を行うことを特徴とするものであって、Ａｌ
粉末合金の結晶粒径を０．３ｍｍ以下としたので、粒界
面積が大きく粒界に脆い金属間化合物を生成し強度を低
下させる液相の影響が少なくなり、局部溶解温度以上に
加熱しても強度低下が小さく、さらに焼割れが発生する
こともない。そのため、溶体化温度を局部溶解温度±５
℃まで上昇することができるので、Ｃｕ、Ｍｇあるいは
さらに通常添加されるＳｉ等の添加元素の固溶量を増大
することができ、その後の時効硬化処理により疲労強度
が向上し、バルブリフタやバルブスプリングリテーナ等
の動弁系部品として実用化できる程度に高強度のＡｌ粉
末合金を得ることができる。As described above, the heat treatment method for an Al powder alloy according to the present invention comprises, as described above, a precipitation hardening type heat treatment Al-Cu-Mg-based Al powder alloy having a crystal grain size of 0.3 mm or less.
A solution treatment is performed within a range of ± 5 ° C. of a local melting temperature, and thereafter, age hardening is performed.
Since the crystal grain size of the powder alloy is set to 0.3 mm or less, the influence of the liquid phase that reduces the strength by generating a brittle intermetallic compound at the grain boundary and reducing the strength is reduced. Also, there is little decrease in strength, and there is no occurrence of burning cracks. Therefore, the solution temperature is set to the local melting temperature ± 5.
° C, so that the solid solution amount of additional elements such as Cu, Mg or more commonly added Si can be increased, and the fatigue strength is improved by the subsequent age hardening treatment. It is possible to obtain an Al powder alloy having such a high strength that it can be put to practical use as a valve train component such as a retainer.
【図１】本発明のＡｌ粉末合金（Ｐ／Ｍ材）と従来のＡ
ｌインゴット合金（Ｉ／Ｍ材）の溶体化温度と強度（疲
労強度）の関係を示す線図である。FIG. 1 shows an Al powder alloy (P / M material) of the present invention and a conventional A
FIG. 3 is a diagram showing the relationship between solution temperature and strength (fatigue strength) of 1 ingot alloy (I / M material).
【図２】Ａｌ粉末合金の塑性加工による加工率と結晶粒
径との関係を示す線図である。FIG. 2 is a diagram showing the relationship between the working ratio of Al powder alloy by plastic working and the crystal grain size.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 近藤 幹夫 愛知県愛知郡長久手町大字長湫字横道41 番地の１ 株式会社豊田中央研究所内 (72)発明者 伊東 一彦 愛知県愛知郡長久手町大字長湫字横道41 番地の１ 株式会社豊田中央研究所内 (72)発明者 石原 知 愛知県愛知郡長久手町大字長湫字横道41 番地の１ 株式会社豊田中央研究所内 (72)発明者 大久保 喜正 東京都港区新橋５丁目11番３号 住友軽 金属工業株式会社内 (72)発明者 佐野 秀男 東京都港区新橋５丁目11番３号 住友軽 金属工業株式会社内 (72)発明者 菊地 昭雄 東京都港区新橋５丁目11番３号 住友軽 金属工業株式会社内 (58)調査した分野(Int.Cl.7，ＤＢ名) B22F 3/24 C22C 21/00 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Mikio Kondo 41-cho, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory Co., Ltd. 41 at Yokomichi, Toyota Central Research Laboratory Co., Ltd. (72) Inventor Satoshi Ishihara 41, Yokocho, Nagakute-machi, Aichi-gun, Aichi Prefecture Yokomichi 41 at Toyota Central Research Laboratory Co., Ltd. 5-11-3 Sumitomo Light Metal Industry Co., Ltd. (72) Inventor Hideo Sano 5-11-3 Sumitomo Light Metal Industry Co., Ltd. 5-72-3 Sumitomo Light Metal Industry Co., Ltd. (72) Inventor Akio Kikuchi Shimbashi, Minato-ku, Tokyo 5-11-3 Sumitomo Light Metal Industries, Ltd. (58) Field surveyed (Int. Cl. 7 , DB name) B22F 3/24 C22C 21/00
Claims (1)
熱処理用Ａｌ−Ｃｕ−Ｍｇ系Ａｌ粉末合金を、局部溶解
温度の±５℃の範囲で溶体化処理を施し、その後時効硬
化を行うことを特徴とするＡｌ粉末合金の熱処理方法。1. A precipitation hardening type Al-Cu-Mg-based Al powder alloy having a crystal grain size of 0.3 mm or less is subjected to a solution treatment within a range of a local melting temperature of ± 5 ° C., and then is subjected to age hardening. A heat treatment method for an Al powder alloy, which is performed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4022759A JP3005354B2 (en) | 1992-02-07 | 1992-02-07 | Heat treatment method of Al powder alloy |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4022759A JP3005354B2 (en) | 1992-02-07 | 1992-02-07 | Heat treatment method of Al powder alloy |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05222409A JPH05222409A (en) | 1993-08-31 |
| JP3005354B2 true JP3005354B2 (en) | 2000-01-31 |
Family
ID=12091613
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4022759A Expired - Fee Related JP3005354B2 (en) | 1992-02-07 | 1992-02-07 | Heat treatment method of Al powder alloy |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3005354B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103422035A (en) * | 2012-09-20 | 2013-12-04 | 中南大学 | Creep aging forming method for Al-Cu-Mg alloy plate |
-
1992
- 1992-02-07 JP JP4022759A patent/JP3005354B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103422035A (en) * | 2012-09-20 | 2013-12-04 | 中南大学 | Creep aging forming method for Al-Cu-Mg alloy plate |
| CN103422035B (en) * | 2012-09-20 | 2015-08-26 | 中南大学 | A kind of creep age forming method for Al-Cu-Mg alloy sheet material |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05222409A (en) | 1993-08-31 |
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