JP3232685B2 - Manufacturing method of aluminum powder forgings - Google Patents
Manufacturing method of aluminum powder forgingsInfo
- Publication number
- JP3232685B2 JP3232685B2 JP24313292A JP24313292A JP3232685B2 JP 3232685 B2 JP3232685 B2 JP 3232685B2 JP 24313292 A JP24313292 A JP 24313292A JP 24313292 A JP24313292 A JP 24313292A JP 3232685 B2 JP3232685 B2 JP 3232685B2
- Authority
- JP
- Japan
- Prior art keywords
- back pressure
- powder
- forging
- forged product
- extruded
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000005242 forging Methods 0.000 title claims description 60
- 238000004519 manufacturing process Methods 0.000 title claims description 28
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims description 21
- 238000000034 method Methods 0.000 claims description 54
- 239000000843 powder Substances 0.000 claims description 44
- 238000003825 pressing Methods 0.000 claims description 19
- 229910000838 Al alloy Inorganic materials 0.000 claims description 18
- 238000000465 moulding Methods 0.000 claims description 9
- 238000001125 extrusion Methods 0.000 claims description 7
- 239000011812 mixed powder Substances 0.000 claims description 6
- 238000007796 conventional method Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 229910018125 Al-Si Inorganic materials 0.000 description 1
- 229910018520 Al—Si Inorganic materials 0.000 description 1
- 229910017818 Cu—Mg Inorganic materials 0.000 description 1
- 229910018619 Si-Fe Inorganic materials 0.000 description 1
- 229910008289 Si—Fe Inorganic materials 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
Landscapes
- Powder Metallurgy (AREA)
Description
【０００１】[0001]
【産業上の利用分野】この発明は、機械的特性に優れた
急冷アルミニウム合金粉末を用いた鍛造品の製造方法に
関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a forged product using a quenched aluminum alloy powder having excellent mechanical properties.
【０００２】[0002]
【従来の技術】アルミニウム合金粉末に背圧を付加させ
ながら緻密化および成形を行なう粉末鍛造法は、本願発
明と同一の発明者によって開発され、特開平４−１３６
１０５号公報に開示されている。このアルミニウム粉末
鍛造品の製造方法においては、まず、アルミニウム合金
粉末が予め所定の形状に成形され、予備成形体が製造さ
れる。その後、その予備成形体が加熱され、成形用金型
に充填され、予備成形体の押出し成形される押出し部分
の先端部にその押出し部分が押出される方向と逆方向に
背圧を加えつつ、予備成形体が加圧され焼結されて鍛造
品が製造される。2. Description of the Related Art A powder forging method for performing densification and compaction while applying back pressure to an aluminum alloy powder was developed by the same inventor as the present invention, and disclosed in Japanese Patent Application Laid-Open No. 4-136.
No. 105 is disclosed. In the method for manufacturing an aluminum powder forged product, first, an aluminum alloy powder is formed into a predetermined shape in advance, and a preform is manufactured. Thereafter, the preformed body is heated, filled in a molding die, and while applying a back pressure to the tip of the extruded portion of the preformed body to be extruded, in a direction opposite to the direction in which the extruded portion is extruded, The preform is pressed and sintered to produce a forged product.
【０００３】上記の製造方法の鍛造工程において背圧を
加える方法として以下の２つの方法が示されている。The following two methods have been disclosed as methods for applying a back pressure in the forging step of the above-mentioned manufacturing method.
【０００４】（１） 鍛造加工の初めから終わりまで加
えられる背圧の大きさは常に一定である。(1) The magnitude of the back pressure applied from the beginning to the end of forging is always constant.
【０００５】（２） 鍛造加工の終期においては背圧を
大きくして再圧縮し、鍛造品の密度を向上させる。(2) At the end of the forging process, the back pressure is increased and recompression is performed to improve the density of the forged product.
【０００６】このような２つの背圧を加える方法は図５
に示されている。図５は、時間（横軸）に対する背圧の
大きさ（縦軸）の変化を示す。FIG. 5 shows a method of applying such two back pressures.
Is shown in FIG. 5 shows a change in the magnitude of the back pressure (vertical axis) with respect to time (horizontal axis).
【０００７】[0007]
【発明が解決しようとする課題】上記の特開平４−１３
６１０５号公報に開示されたアルミニウム粉末鍛造品の
製造方法は、特にアルミニウム合金粉末の粉末鍛造品の
凸部を健全に成形する方法として開発された方法であ
る。SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. Hei 4-13
The method for manufacturing an aluminum powder forged product disclosed in Japanese Patent No. 6105 is a method developed especially as a method for forming a convex portion of a powder forged aluminum alloy powder soundly.
【０００８】この方法の１つの局面では、背圧が変動せ
ずに常に一定のままで鍛造加工は行なわれる。凸部の高
さが比較的低い鍛造品の製造には、凸部を健全に成形す
る方法として一定の効果を上げることができる。しかし
ながら、凸部の長さが特に長い鍛造品を粉末鍛造または
熱粉鍛造加工によって製造する場合には困難が発生す
る。すなわち、図６に示すように先端割れや密度の小さ
い部分が発生しないように十分大きな背圧を凸部の先端
に付加すると、凸部が最後まで成長できずに途中で成長
が止まってしまい、凸部が所定の長さよりも短い鍛造品
が得られてしまう。逆に、凸部が十分に成長することが
できるように背圧の大きさを低くすると、背圧による効
果が小さくなってしまい、凸部の先端に割れや密度の小
さい部分が発生してしまうという問題点があった。[0008] In one aspect of the method, the forging is performed while the back pressure remains constant without fluctuation. For the production of a forged product in which the height of the projections is relatively low, a certain effect can be obtained as a method of forming the projections soundly. However, difficulties arise when a forged product having a particularly long convex portion is manufactured by powder forging or hot powder forging. That is, as shown in FIG. 6, if a sufficiently large back pressure is applied to the tip of the convex portion so as not to cause a crack at the tip or a portion with a small density, the convex portion cannot grow to the end and stops growing on the way, A forged product in which the protrusion is shorter than the predetermined length is obtained. Conversely, if the magnitude of the back pressure is reduced so that the convex portion can grow sufficiently, the effect of the back pressure will be reduced, and a crack or a small density portion will occur at the tip of the convex portion. There was a problem.
【０００９】また、上述のアルミニウム粉末鍛造品の製
造方法の別の局面として、鍛造加工の終期において背圧
を大きくして再圧縮し、鍛造品の密度を向上させる方法
（２）がある。この方法によれば、鍛造加工の初めから
終わりまで常に背圧を一定にさせる方法（１）に比べて
鍛造加工の初期において背圧を低く設定することができ
るので、凸部は成長しやすくなる。しかしながら、凸部
が成長しやすくなる分だけ、凸部の先端に割れが入る可
能性が高くなるという欠点があった。アルミニウム合金
粉末の粉末鍛造においては、一旦割れが入った鍛造品を
その後の加圧において完全に接着させることは不可能で
ある。Another aspect of the above-described method for manufacturing an aluminum powder forged product is a method (2) for increasing the back pressure at the end of forging and recompressing to improve the density of the forged product. According to this method, the back pressure can be set lower in the initial stage of the forging process than in the method (1) in which the back pressure is always kept constant from the beginning to the end of the forging process, so that the convex portion is easily grown. . However, there is a disadvantage that the possibility of cracking at the tip of the projection increases as much as the projection grows easily. In powder forging of an aluminum alloy powder, it is impossible to completely bond a cracked forged product by subsequent pressing.
【００１０】そこで、この発明の目的は上記のような問
題点を解消することであり、比較的凸部の長さが長い形
状を有する粉末鍛造品においても密度分布が均一で割れ
などが生じることのないアルミニウム粉末鍛造品の製造
方法を提供することである。SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and it is desired that even a powder forging having a relatively long protruding portion has a uniform density distribution and cracks or the like. It is an object of the present invention to provide a method for producing a forged aluminum powder without any problem.
【００１１】[0011]
【課題を解決するための手段】この発明の１つの局面に
従ったアルミニウム粉末鍛造品の製造方法は、アルミニ
ウム合金粉末またはアルミニウム合金粉末を含む混合粉
末を予め所定の形状に成形した予備成形体を加熱した
後、成形用金型内に充填し、予備成形体の押出し成形さ
れる押出し部分の先端部にその押出し部分が押出される
方向と逆方向に背圧を加えつつ予備成形体を加圧し焼結
させて鍛造加工する方法において以下のことを特徴とす
る。鍛造加工の初期には第１の背圧を加え、その後瞬時
に背圧を低下させることにより、鍛造加工の終期には第
１の背圧よりも小さい第２の背圧を加える。According to one aspect of the present invention, there is provided a method for manufacturing an aluminum powder forging, comprising the steps of: forming a preform in which aluminum alloy powder or a mixed powder containing aluminum alloy powder is previously formed into a predetermined shape; After heating, the preform is filled in a molding die, and the preform is pressed while applying a back pressure to the tip of the extruded portion of the preform in the direction opposite to the direction in which the extruded portion is extruded. The method for sintering and forging is characterized by the following. The first back pressure is applied at the beginning of the forging process, and the back pressure is reduced immediately thereafter, so that the second back pressure smaller than the first back pressure is applied at the end of the forging process.
【００１２】この発明のもう１つの局面に従ったアルミ
ニウム粉末鍛造品の製造方法は、アルミニウム合金粉末
またはアルミニウム合金粉末を含む混合粉末を加熱した
後、成形用金型内に充填し、押出し成形される押出し部
分の先端部にその押出し部分が押出される方向と逆方向
に背圧を加えつつ粉末を加圧して焼結させて鍛造加工す
る方法において以下のことを特徴とする。鍛造加工の初
期には第１の背圧を加え、その後瞬時に背圧を低下させ
ることにより、鍛造加工の終期には第１の背圧よりも小
さい第２の背圧を加える。According to another aspect of the present invention, there is provided a method for manufacturing an aluminum powder forged product, comprising heating an aluminum alloy powder or a mixed powder containing the aluminum alloy powder, filling the mixture into a molding die, and extruding. The method for forging by pressing and sintering the powder while applying a back pressure to the tip of the extruded portion in a direction opposite to the direction in which the extruded portion is extruded is characterized as follows. The first back pressure is applied at the beginning of the forging process, and the back pressure is reduced immediately thereafter, so that the second back pressure smaller than the first back pressure is applied at the end of the forging process.
【００１３】好ましくは、予備成形体の押出し部分の先
端部、または粉末の押出し部分の先端部に加えられる背
圧は、予備成形体を加圧する圧力または粉末を加圧する
圧力に比べて低く設定されている。予備成形体または粉
末の鍛造加工は前方押出し法および後方押出し法のいず
れかの方法で行なわれる。予備成形体は真密度比６０％
以上９０％以下に成形され、鍛造品は真密度比９５％以
上に成形される。[0013] Preferably, the back pressure applied to the tip of the extruded portion of the preform or the tip of the extruded portion of the powder is set lower than the pressure for pressing the preform or the pressure for pressing the powder. ing. The forging of the preform or the powder is performed by any one of a forward extrusion method and a backward extrusion method. Preformed body is 60% true density ratio
The forged product is formed to a true density ratio of 95% or more.
【００１４】[0014]
【作用】この発明においては、鍛造加工において背圧
は、たとえば約０．７秒間という短い鍛造時間の初期に
背圧を高く設定しておき、鍛造時間の終期には背圧を低
く変化させる。まず、鍛造加工の初期には背圧を大きく
設定しておくことによって凸部先端に十分な圧力をかけ
て割れや密度の小さい部分の発生を防止する。その後、
瞬時に背圧を低下させることによって、凸部の成長を妨
げる逆方向の圧力を少なくして、凸部を十分に成長させ
ようとするものである。時間に対する背圧の大きさの変
化は図１に示される。図１においては、従来の（１）お
よび（２）の方法と合わせて本発明の方法における背圧
の大きさの変化が示されている。According to the present invention, in the forging process, the back pressure is set high at the beginning of a short forging time of, for example, about 0.7 seconds, and the back pressure is changed low at the end of the forging time. First, by setting a large back pressure in the early stage of forging, sufficient pressure is applied to the tip of the convex portion to prevent the occurrence of cracks and low density portions. afterwards,
By instantaneously lowering the back pressure, the pressure in the reverse direction that hinders the growth of the convex portion is reduced, and the convex portion is sufficiently grown. The change in the magnitude of the back pressure over time is shown in FIG. FIG. 1 shows the change in the magnitude of the back pressure in the method of the present invention in combination with the conventional methods (1) and (2).
【００１５】この発明の方法において背圧を変化させた
場合、凸部先端の割れや密度の小さい部分の発生が防止
されても、背圧を低下させたときに張出し途中の部分で
割れが発生することが懸念される。本願発明者らはこの
点に関して種々のシミュレーションを行ない、一旦凸部
が張出すように成形されてしまうと、鍛造品の凸部の壁
面と鍛造品の凹部の壁面との間に摩擦力が働き、この摩
擦力が張出し部に発生するはずの引張り応力を相殺する
ことを見出した。この発明のアルミニウム粉末鍛造品の
製造方法は、以上の本願発明者らの知見に基づいてなさ
れたものである。When the back pressure is changed in the method of the present invention, even if cracks at the tips of the convex portions and portions having a low density are prevented from occurring, cracks occur at portions in the middle of overhang when the back pressure is reduced. It is feared that. The inventors of the present application performed various simulations on this point, and once the protrusion was formed so as to protrude, a frictional force acts between the wall surface of the protrusion of the forged product and the wall surface of the recess of the forged product. It has been found that this frictional force cancels out the tensile stress that would occur at the overhang. The method for producing an aluminum powder forged product of the present invention has been made based on the above findings of the present inventors.
【００１６】さらに、従来の背圧を変化させない方法
（定背圧法：図１の（１）の方法）によれば、凸部の成
長を促すためにあまり大きな背圧を加えることはできな
かった。一方、本発明の方法、背圧を変化させる方法
（可変背圧法）によれば、鍛造加工の初期において大き
な背圧を加えても、その後の背圧の低下によって凸部の
成長が可能であるため、鍛造加工の初期に加えられる大
きな背圧によって凸部の割れを防止し、密度を向上させ
ることができる。このような作用は、たとえば図２にお
いて時間に対する背圧の変化と共に示され得る。図２に
示すように、比較的高い背圧が加えられる鍛造加工の初
期において先端部の固化、すなわち凸部の割れの防止と
凸部の密度の向上が図られ、比較的低い背圧が加えられ
る鍛造加工の終期において凸部の成長が図られる。Further, according to the conventional method in which the back pressure is not changed (constant back pressure method: method (1) in FIG. 1), it is not possible to apply an excessively large back pressure in order to promote the growth of the projection. . On the other hand, according to the method of the present invention and the method of changing the back pressure (variable back pressure method), even if a large back pressure is applied in the early stage of forging, the growth of the convex portion can be achieved by a decrease in the back pressure. Therefore, it is possible to prevent the projections from being cracked by a large back pressure applied in the early stage of forging, and to improve the density. Such an effect can be shown, for example, in FIG. 2 with a change in back pressure over time. As shown in FIG. 2, in the initial stage of forging in which a relatively high back pressure is applied, solidification of the tip, that is, prevention of cracks in the protrusions and improvement in the density of the protrusions, are achieved. At the end of the forging process, the projections are grown.
【００１７】なお、本発明の粉末鍛造品の原料として用
いられるアルミニウム合金粉末とはＡｌ−Ｓｉ系やＡｌ
−Ｓｉ−Ｆｅ系やＡｌ−Ｓｉ−Ｃｕ−Ｍｇ系などの組成
のエアアトマイズ粉末や急冷リボンの粉砕粉末などをい
う。アルミニウム合金粉末を含む混合粉末とは、上記の
粉末に潤滑性能を付加するＣｒ粉末、耐熱性や比強度を
向上させるＳｉＣウィスカ、耐摩耗性を向上させるＡｌ
2 Ｏ3 粒子などを混合添加したものをいう。The aluminum alloy powder used as a raw material of the powder forged product of the present invention refers to an Al—Si or Al
-Atomized powder having a composition such as -Si-Fe or Al-Si-Cu-Mg or crushed powder of a quenched ribbon. The mixed powder containing the aluminum alloy powder is a Cr powder that adds lubrication performance to the above powder, a SiC whisker that improves heat resistance and specific strength, and an Al that improves wear resistance.
It refers to a mixture of 2 O 3 particles and the like.
【００１８】また、予備成形体の真密度比が６０％未満
では型押し体が脆く、ハンドリングの際に崩壊したり、
欠けたりする恐れがあるので、鍛造加工される予備成形
体の真密度比は６０％以上が好ましい。また、予備成形
体の真密度比が９０％を超えると、予備成形体の成形に
おいて大きな圧力を必要とするため、経済的でないの
で、予備成形体の真密度比は９０％以下であるのが好ま
しい。さらに、鍛造品の真密度比を９５％以上にする理
由は、この値以上の密度にしなければ鍛造品の強度が低
くなるからである。If the true density ratio of the preform is less than 60%, the embossed body is brittle and may collapse during handling,
Because of the possibility of chipping, the true density ratio of the preformed body to be forged is preferably 60% or more. On the other hand, if the true density ratio of the preform exceeds 90%, a large pressure is required for molding the preform, which is not economical. Therefore, the true density ratio of the preform is 90% or less. preferable. Further, the reason why the true density ratio of the forged product is set to 95% or more is that the strength of the forged product becomes low unless the density is equal to or more than this value.
【００１９】[0019]
【実施例】以下、この発明の一実施例について図を用い
てまず概略的に説明する。図３の（Ａ）〜（Ｅ）は、こ
の発明の製造方法における鍛造工程を順に示す工程断面
図である。この製造工程においては、後方押出し法を用
いて円板表面に突出部を有する形状の鍛造品を形成する
工程が例示されている。DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be schematically described below with reference to the drawings. 3A to 3E are process cross-sectional views sequentially showing a forging process in the manufacturing method of the present invention. In this manufacturing process, a process of forming a forged product having a protruding portion on the surface of a disk using a backward extrusion method is exemplified.
【００２０】まず、アルミニウム合金粉末またはアルミ
ニウム合金粉末を含む混合粉末を加圧して比較的単純な
形状を有する予備成形体を成形する。この予備成形体
は、真密度比６０％以上９０％以下となるように成形さ
れる。次に、予備成形体を５００℃程度に予備加熱す
る。その後、図３に従って粉末鍛造成形を行なう。First, the aluminum alloy powder or the mixed powder containing the aluminum alloy powder is pressed to form a preform having a relatively simple shape. This preformed body is formed so as to have a true density ratio of 60% or more and 90% or less. Next, the preform is preheated to about 500 ° C. Thereafter, powder forging is performed according to FIG.
【００２１】図３の（Ａ）を参照して、成形用金型は上
型２と下型６とを備える。下型６の内部には予備成形体
１が充填される。上型２は予備成形体１の表面を圧縮成
形するための第１加圧体３と押出し部分を成形するため
の第２加圧体４および第２加圧体に加圧力を付与するた
めのシリンダ５とを有している。Referring to FIG. 3A, the molding die includes an upper die 2 and a lower die 6. The preform 1 is filled in the lower mold 6. The upper die 2 is for applying a pressing force to the first pressing body 3 for compression-molding the surface of the preform 1 and the second pressing body 4 and the second pressing body for forming the extruded portion. And a cylinder 5.
【００２２】次に、図３の（Ｂ）を参照して、上型２を
下降し予備成形体１の表面に当接して加圧動作を開始す
る。Next, referring to FIG. 3 (B), the upper mold 2 is lowered and brought into contact with the surface of the preform 1 to start the pressing operation.
【００２３】さらに、図３の（Ｃ）を参照して、第１加
圧体３がＦ1 ＝８ｔｏｎ／ｃｍ2 、第２加圧体４がＦ2
＝６ｔｏｎ／ｃｍ2 の圧力で予備成形体１を加圧する。
第１加圧体３の加圧により、予備成形体１は、第２加圧
体４から背圧Ｆ2 を受けながら押出し部分１ａが、第１
加圧体３と反対方向に押出される。押出し部分１ａは第
２加圧体４からの背圧により、先端部に亀裂が生じるこ
となく成形される。Further, referring to FIG. 3C, the first pressure member 3 is F 1 = 8 ton / cm 2 , and the second pressure member 4 is F 2
The preform 1 is pressed at a pressure of = 6 ton / cm 2 .
The pressure of the first pressing body 3, the preform 1 is extruded portion 1a is while receiving back pressure F 2 from the second pressure member 4, the first
It is extruded in the direction opposite to the pressure body 3. The extruded portion 1a is formed by the back pressure from the second pressurizing member 4 without cracking at the tip.
【００２４】さらに、鍛造時間（約０．７秒）の後期
（約０．３秒）には第２加圧体の圧力が瞬時に低下させ
られ、図３の（Ｅ）に示すように、第２加圧体４がＦ3
＝０．５ｔｏｎ／ｃｍ2 の圧力で予備成形体１を加圧す
る。第１加圧体３の圧力はＦ1のままである。このよう
に、鍛造加工の後期においては、第１加圧体３の加圧に
より、予備成形体１は、第２加圧体４から低い背圧Ｆ3
を受けながら押出し部分１ａが、第１加圧体３の加圧方
向と反対方向に押出される。押出し部分１ａは第２加圧
体４からの背圧により凸部の十分な成長が可能となる。Further, in the latter period (approximately 0.3 seconds) of the forging time (approximately 0.7 seconds), the pressure of the second pressing body is instantaneously reduced, and as shown in FIG. The second pressing body 4 is F 3
= 0.5 ton / cm 2 is applied to the preform 1. Pressure of the first pressing body 3 remains F 1. As described above, in the later stage of the forging process, the preform 1 is pressed from the second pressing body 4 by the back pressure F 3
While being received, the extruded portion 1a is extruded in the direction opposite to the direction in which the first pressing body 3 is pressed. In the extruded portion 1a, the back pressure from the second pressurizing member 4 allows the convex portion to grow sufficiently.
【００２５】以下、上述の本発明の可変背圧法と従来の
定背圧法（背圧の大きさに変化なし）とを用いてアルミ
ニウム合金粉末を鍛造した実施例および比較例について
説明する。Hereinafter, examples and comparative examples in which aluminum alloy powder is forged using the above-described variable back pressure method of the present invention and the conventional constant back pressure method (no change in the magnitude of the back pressure) will be described.
【００２６】Ａｌ−２０Ｓｉ−５Ｆｅ−２Ｎｉ−３Ｃｕ
−１Ｍｇ（重量％）組成のエアアトマイズ粉末を用い
て、図４に示される予備成形体（Ａ〜Ｃ）に型押しした
ものと、粉末そのままの状態のもの（Ｄ）を準備した。
これらを５００℃に加熱した後、それぞれ図４に示す形
状に粉末鍛造（Ａ〜Ｃ）、熱粉鍛造（Ｄ）した。Al-20Si-5Fe-2Ni-3Cu
An air atomized powder having a composition of -1 Mg (% by weight) was embossed into preforms (A to C) shown in FIG. 4 and a powder as it was (D) was prepared.
After these were heated to 500 ° C., powder forging (A to C) and hot powder forging (D) were performed respectively into the shapes shown in FIG.
【００２７】サンプルごとにｈA ，ｈB ，ｈC ，ｈD の
高さを変化させて、定背圧法（背圧変化なし）と可変背
圧法（本発明）を用いて鍛造し、凸部先端の割れ発生の
有無および凸部先端の密度を調べた。The height of h A , h B , h C , and h D is changed for each sample, and forging is performed using a constant back pressure method (no change in back pressure) and a variable back pressure method (the present invention). The presence or absence of cracks at the tip and the density at the tip of the projection were examined.
【００２８】なお、定背圧法では、鍛造圧力を８ｔｏｎ
／ｃｍ2 、背圧を６ｔｏｎ／ｃｍ2に設定して鍛造加工
を行なった。しかし、定背圧法では、凸部の長さを長く
設計した金型を用いて鍛造加工を行なうと、鍛造品の凸
部の長さが所定の長さにならなかった。そこで、定背圧
法を用いた鍛造加工においては、凸部の長さが所定の長
さになるような圧力に背圧を低下させて鍛造加工を行な
った。In the constant back pressure method, the forging pressure is set at 8 tons.
/ Cm 2 , and the back pressure was set at 6 ton / cm 2 , and forging was performed. However, in the constant back pressure method, when forging is performed using a mold designed to have a long convex portion, the length of the convex portion of the forged product does not become a predetermined length. Therefore, in the forging using the constant back pressure method, the forging is performed by reducing the back pressure to a pressure such that the length of the convex portion becomes a predetermined length.
【００２９】可変背圧法では、鍛造圧力が８ｔｏｎ／ｃ
ｍ2 で、背圧は鍛造加工の初期においては６ｔｏｎ／ｃ
ｍ2 を付加し、鍛造時間（約０．７秒）の後期（約０．
３秒）には０．５ｔｏｎ／ｃｍ2 に低下させた。得られ
た鍛造体の凸部先端の割れの状況を観察し、密度を調べ
た結果は表１に示される。In the variable back pressure method, the forging pressure is 8 ton / c.
m 2 , back pressure is 6 ton / c at the beginning of forging
m 2 , and the forging time (approximately 0.7 seconds) in the latter period (approx.
(3 seconds), it was reduced to 0.5 ton / cm 2 . Table 1 shows the results of observing the state of cracks at the tips of the convex portions of the obtained forged body and examining the density.
【００３０】[0030]
【表１】 [Table 1]
【００３１】表１から明らかなように、本発明に従って
背圧を変化させる方法によれば、凸部の長さの長短にか
かわらず、割れが発生せず、凸部の密度も高い値で維持
されることがわかる。As is clear from Table 1, according to the method of changing the back pressure according to the present invention, no crack occurs and the density of the projections is maintained at a high value regardless of the length of the projections. It is understood that it is done.
【００３２】[0032]
【発明の効果】以上のように本発明によるアルミニウム
粉末鍛造品の製造方法は、予備成形体あるいは原料粉末
の鍛造工程において、押出し部分の先端部に背圧を付加
した状態で加圧成形を行なうとき、鍛造加工の終期に瞬
時に背圧を変化させることにより、鍛造加工の初期より
も小さい背圧を加えるようにしている。そのため、比較
的長い凸部を有する鍛造品においても凸部先端の割れや
密度不均一の発生を防止し、強度を高めることが可能に
なる。したがって、凸部を有する複雑な形状のアルミニ
ウム粉末鍛造品を所定の形状どおりに製造することが可
能となる。As described above, in the method for producing an aluminum powder forging according to the present invention, in the step of forging a preform or a raw material powder, pressure molding is performed with a back pressure applied to the tip of the extruded portion. At this time, the back pressure is changed instantaneously at the end of the forging to apply a back pressure smaller than that at the beginning of the forging. Therefore, even in a forged product having a relatively long projection, it is possible to prevent cracks at the tip of the projection and uneven density, and to increase the strength. Therefore, it becomes possible to manufacture an aluminum powder forged product having a complicated shape having a convex portion according to a predetermined shape.
【図１】この発明によるアルミニウム粉末鍛造品の製造
方法の鍛造加工における時間に対する背圧の大きさの変
化を、従来の方法と合わせて示すグラフである。FIG. 1 is a graph showing a change in the magnitude of back pressure with respect to time in forging in a method for manufacturing an aluminum powder forged product according to the present invention, together with a conventional method.
【図２】この発明の製造方法における鍛造時間と背圧と
の関係の一例を示すグラフである。FIG. 2 is a graph showing an example of a relationship between a forging time and a back pressure in the manufacturing method of the present invention.
【図３】この発明の製造方法における鍛造工程を順に示
す工程断面図である。FIG. 3 is a process sectional view sequentially showing a forging process in the manufacturing method of the present invention.
【図４】実施例と比較例に従って成形される予備成形体
と粉末鍛造品を示す外観図である。FIG. 4 is an external view showing a preform and a powder forged product formed according to an example and a comparative example.
【図５】従来のアルミニウム粉末鍛造品の製造方法の鍛
造加工において時間に対する背圧の大きさの変化を示す
グラフである。FIG. 5 is a graph showing a change in the magnitude of the back pressure with respect to time in forging in a conventional method for manufacturing an aluminum powder forged product.
【図６】従来の鍛造加工において背圧と時間との関係を
問題点と共に示すグラフである。FIG. 6 is a graph showing the relationship between back pressure and time in a conventional forging process together with problems.
図において、１は予備成形体、１ａは押出し部分、２は
上型、３は上型２の第１加圧体、４は第２加圧体を示
す。In the drawing, reference numeral 1 denotes a preformed body, 1a denotes an extruded portion, 2 denotes an upper die, 3 denotes a first pressing body of the upper die 2, and 4 denotes a second pressing body.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 林 哲也 兵庫県伊丹市昆陽北一丁目１番１号 住 友電気工業株式会社 伊丹製作所内 (58)調査した分野(Int.Cl.7，ＤＢ名) B22F 3/035 B22F 3/20 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tetsuya Hayashi 1-1-1 Kunyokita, Itami-shi, Itami-shi, Hyogo Itami Works, Sumitomo Electric Industries, Ltd. (58) Field surveyed (Int. Cl. 7 , DB name) ) B22F 3/035 B22F 3/20
Claims (7)
ム合金粉末を含む混合粉末を予め所定の形状に成形した
予備成形体を加熱した後、成形用金型内に充填し、前記
予備成形体の押出し成形される押出し部分の先端部にそ
の押出し部分が押出される方向と逆方向に背圧を加えつ
つ前記予備成形体を加圧し焼結させて鍛造加工するアル
ミニウム粉末鍛造品の製造方法において、 前記鍛造加工の初期には第１の背圧を加え、その後瞬時
に背圧を低下させることにより、前記鍛造加工の終期に
は前記第１の背圧よりも小さい第２の背圧を加えること
を特徴とする、アルミニウム粉末鍛造品の製造方法。1. A preform formed by molding an aluminum alloy powder or a mixed powder containing an aluminum alloy powder into a predetermined shape in advance is heated and then filled into a molding die, and the preform is extruded. A method for producing an aluminum powder forged product in which the preformed body is pressed, sintered and forged by applying a back pressure to the tip of the extruded part in a direction opposite to a direction in which the extruded part is extruded, The first back pressure is applied at an early stage, and then the back pressure is reduced instantaneously. At the end of the forging, a second back pressure smaller than the first back pressure is applied. , Manufacturing method of aluminum powder forgings.
加えられる前記背圧は、前記予備成形体を加圧する圧力
に比べて低く設定されている、請求項１に記載のアルミ
ニウム粉末鍛造品の製造方法。2. The aluminum powder forging according to claim 1, wherein the back pressure applied to the tip of the extruded portion of the preform is set lower than the pressure for pressing the preform. Manufacturing method.
し法および後方押出し法のいずれかの方法で行なわれ
る、請求項１または２に記載のアルミニウム粉末鍛造品
の製造方法。3. The method for producing an aluminum powder forged product according to claim 1, wherein the forging of the preform is performed by one of a forward extrusion method and a backward extrusion method.
０％以下に成形され、前記鍛造品は真密度比９５％以上
に成形される、請求項１ないし３のいずれかに記載のア
ルミニウム粉末鍛造品の製造方法。4. The pre-formed body has a true density ratio of not less than 60% and not less than 9%.
The method for producing an aluminum powder forged product according to any one of claims 1 to 3, wherein the forged product is formed to have a true density ratio of 95% or more.
ム合金粉末を含む混合粉末を加熱した後、成形用金型内
に充填し、押出し成形される押出し部分の先端部にその
押出し部分が押出される方向と逆方向に背圧を加えつつ
前記粉末を加圧して焼結させて鍛造加工するアルミニウ
ム粉末鍛造品の製造方法において、 前記鍛造加工の初期には第１の背圧を加え、その後瞬時
に背圧を低下させることにより、前記鍛造加工の終期に
は前記第１の背圧よりも小さい第２の背圧を加えること
を特徴とする、アルミニウム粉末鍛造品の製造方法。5. An aluminum alloy powder or a mixed powder containing an aluminum alloy powder is heated and then filled into a molding die, and the tip of the extruded portion to be extruded is opposite to the direction in which the extruded portion is extruded. In a method for manufacturing an aluminum powder forged product in which the powder is pressed and sintered while applying a back pressure in the direction, the first back pressure is applied in an early stage of the forging, and then the back pressure is instantaneously increased. A method for producing an aluminum powder forged product, characterized in that a second back pressure smaller than the first back pressure is applied at the end of the forging by lowering the pressure.
れる前記背圧は、前記粉末を加圧する圧力に比べて低く
設定されている、請求項５に記載のアルミニウム粉末鍛
造品の製造方法。6. The method for manufacturing an aluminum powder forged product according to claim 5, wherein the back pressure applied to the tip of the extruded portion of the powder is set lower than the pressure for pressing the powder.
よび後方押出し法のいずれかの方法で行なわれる、請求
項５または６に記載のアルミニウム粉末鍛造品の製造方
法。7. The method for producing an aluminum powder forged product according to claim 5, wherein the forging of the powder is performed by one of a forward extrusion method and a backward extrusion method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24313292A JP3232685B2 (en) | 1992-09-11 | 1992-09-11 | Manufacturing method of aluminum powder forgings |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24313292A JP3232685B2 (en) | 1992-09-11 | 1992-09-11 | Manufacturing method of aluminum powder forgings |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0693303A JPH0693303A (en) | 1994-04-05 |
| JP3232685B2 true JP3232685B2 (en) | 2001-11-26 |
Family
ID=17099280
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24313292A Expired - Fee Related JP3232685B2 (en) | 1992-09-11 | 1992-09-11 | Manufacturing method of aluminum powder forgings |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3232685B2 (en) |
-
1992
- 1992-09-11 JP JP24313292A patent/JP3232685B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0693303A (en) | 1994-04-05 |
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