JP2568105B2 - Method for hot extrusion of Al-based rapidly solidified powder alloy - Google Patents

Description

TECHNICAL FIELD The present invention relates to an extrusion molding method of an Al-based rapidly solidified powder alloy.

(Prior Art) Al-based rapidly solidified powder alloys are used for automobile engine parts and the like because they have a fine structure, are excellent in strength, and are lightweight. In the molding of the alloy, an Al-based rapidly solidified powder was usually obtained by compression molding by cold isostatic pressing (referred to as CIP) and then pressure sintering by hot isostatic pressing (referred to as HIP). The material is formed by extrusion. In the extrusion molding, since the Al-based rapidly solidified powder alloy has a proper strength due to its property by giving plastic flow while being heated, hot extrusion molding is usually performed.

As the hot extrusion molding apparatus, those shown in FIGS. 5 to 7 are conventionally known. In the device, the fifth
Die 2 heated by heater 1 as shown
The material 4 filled in the cavity 3 inside is punched by the punch 5.
Then, it is plastically flowed by being pressed by, and is extruded from the molding round 7 through the narrowing portion 6 provided to reduce the pressing resistance, and is molded as shown in FIG. After the molding, the molded product 4a is ejected in the direction opposite to the pressing by the knockout means 8 as shown in FIG.

However, in the above-mentioned molding, since the material 4 remains in the narrowed portion 6 without being extruded from the molding round 7, the molded product 4a has an unpressed part A as shown in FIG. 7, and the unpressed part A is unformed. It is unnecessary because it is a part. Further, since the tip end portion B of the molded product 4a has insufficient plastic flow and the strength is not improved, and further the tip end portion B is likely to be cracked,
Not used Therefore, the effective portion C used in the molded product 4a is the portion excluding the end portions A and B, and particularly in the case of molding in which the extrusion amount is small, the effective portion C for the material 4 is
Low yield and poor yield.

Further, in the above-mentioned molding, a lubricant is applied to the inner wall of the cavity 3 in order to prevent the seizure of the material 4 and the die 2. However, the lubricating film becomes thin during the molding, and the molded product 4a is knocked out by the knockout means 8. Molding round 7 when ejected
It is easy for seizure to occur in the drawing portion 6.

(Problems to be solved) The present invention, in the hot extrusion molding of Al-based rapidly solidified powder alloy, eliminates such inconvenience, it is possible to improve the yield of molding and prevent seizure, further cracks and the like. It is an object of the present invention to provide a method capable of preventing defective molding.

(Means for Solving the Problems) In the hot extrusion molding method of an Al-based rapidly solidified powder alloy according to the present invention, a dummy metal different in material from the material is provided at the end of the material made of Al-based rapidly solidified powder alloy. In a state where the material and the dummy metal are heated, the material is pressed through the dummy metal and extruded from the molding round through the narrowed portion narrowed in the pressing direction to be molded. The amount of dummy metal or the amount of pressing stroke is adjusted so that only the dummy metal remains in the narrowed portion after the molding.

Further, in the hot extrusion molding method of the Al-based rapidly solidified powder alloy of the present invention, the forming is performed again after the forming with the dummy metal left in the drawn portion.

(Operation) In the above-mentioned method, the material is pressed through the dummy metal to be molded, and after the molding, only the dummy metal is left in the drawing portion, so that the material is all passed through the molding round to be molded. Also, because the dummy metal is a different material than the material, after the material has passed the molding round,
The material and the dummy metal are naturally separated and taken out.

Further, the molding can be continuously performed by performing the molding with the dummy metal left in the narrowed portion. Further, the presence of the dummy metal left in the narrowed portion serves as an extrusion resistance to bring about a hydrostatic effect, the strength of the tip portion of the molded product is enhanced, and the occurrence of cracks and the like is prevented.

(Example) A first example of the hot extrusion molding method for an Al-based rapidly solidified powder alloy of the present invention will be described with reference to FIGS. 1 and 2.

In this example, first, an Al-based rapidly solidified powder was compacted into a suitable size, subjected to CIP treatment, and then subjected to HIP treatment. 2 cavity 3 is filled. The die 2 is heated to about 300 ° C. by the heater 1 to prevent the temperature of the material 4 from decreasing. Next, a dummy metal 9 made of an Al-based alloy having a deformation resistance almost equal to that of the material 4 and different from the material 4 is used.
Are heated in the same manner as the material 4 to fill the cavity 3 and are stacked on the material 4. Punch 5 in this state
Is inserted into the cavity 3 from above, and the blank 4 is pressed together with the dummy metal 9. By the pressing, the material 4 and the dummy metal 9 plastically flow, and the material 4 is extruded from the molding round 7 through the narrowed portion 6 and the molded product 4a is molded. In the forming, the pressing by the punch 5 is stopped slightly above the upper end of the narrowed portion 6, and the amount of the dummy metal 9 is adjusted to an appropriate amount in advance. All have passed the forming round 7, the plastic flow of the dummy metal 9 stops near the forming round 7, and the dummy metal 9 is left in the narrowed portion 6. Material 4 is molding round 7
When the pressing is stopped, the molded product 4a that has passed through and is naturally separated from the dummy metal 9 due to the difference in material from the dummy metal 9 and falls, and is taken out from the die 2. Next, the knockout means 8 is inserted into the cavity 3 from below, and the dummy metal 9 left in the narrowed portion 6 is projected upward.

On the other hand, in the above-mentioned molding, molybdenum disulfide is applied as a lubricant to the inner wall of the cavity 3 in order to prevent the die 4 from sticking to the material 4 or the dummy metal 9.
No seizure between the material 4 and the die 2 occurs during molding. In addition, although the lubricating film of molybdenum disulfide is thin after molding, the material of the dummy metal 9 is the die 2 in advance.
Since the seizure of the dummy metal 9 is not likely to occur, the seizure of the dummy metal 9 by the knockout means 8 does not cause any adverse effect.

Next, a second embodiment of the hot extrusion molding method for an Al-based rapidly solidified powder alloy of the present invention will be described with reference to FIGS. 3 and 4. In this embodiment, the same material 4 and dummy metal 9 as those in the first embodiment are used, and the molded product 4a is formed in the same manner as in the first embodiment.
After molding, the dummy metal 9 left in the narrowed portion 6 is left in the narrowed portion 6 as it is without being projected by the knockout means 8. Therefore, in the state where the dummy metal 9 remains in the narrowed portion 6 as shown in FIG. 3, the material 4 and the dummy metal 9 are overlapped and filled in the cavity 3 as in the first embodiment. As shown in the fourth drawing, the punch 5 presses the dummy metal 9 on the upper part of the material 4, and first, the dummy metal 9 left in the drawing part 6 is extruded from the forming round 7 and falls, and then the material 4 is extruded from molding round 7 and molded product 4a
Is molded and falls. The dummy metal 9 superposed on the upper portion of the material 4 is left in the narrowed portion 6. The above molding is continuously performed.

In the above-mentioned molding, since the dummy metal 9 is left in the narrowed portion 6, the extrusion resistance increases, which brings about the hydrostatic effect, which strengthens the strength of the tip portion of the molded product 4a and makes it difficult for cracks to occur. Become. Further, as compared with the first embodiment, the strength of the tip portion B of the molded product 4a is increased, so that the unusable tip portion B becomes shorter and the effective portion C increases.

In the first and second embodiments, the raw material 4 was manufactured by performing the CIP treatment and the HIP treatment. However, one of the both treatments is omitted to manufacture the raw material 4 and perform hot extrusion molding. Is also good. However, in order to obtain better strength of the molded product 4a, it is desirable to perform both the treatments to manufacture the material 4.

Further, although an Al-based alloy having a deformation resistance substantially equal to that of the material 4 is used as the dummy metal 9, the dummy metal 9 is not limited to this and may be selected from one that is unlikely to cause seizure with the die 2.

Furthermore, in hot extrusion molding of Al-based rapidly solidified powder alloy,
It is necessary to keep the raw material 4 at a high temperature, and in the conventional molding without using the dummy metal 9, it was desirable to heat the punch 5 as well, but in the hot extrusion molding method of the present invention, Also, as shown in the second embodiment, since the material 4 is pressed by the punch 5 via the dummy metal 9, it is not necessary to heat the punch 5 in particular.

(Effect of the invention) In the hot extrusion molding method of the Al-based rapidly solidified powder alloy of the present invention, as is clear from the above description, the material made of the Al-based rapidly solidified powder alloy is pressed by the dummy metal and molded. In the state after the forming, only the dummy metal is left in the narrowed portion, so that all the raw materials are extruded from the forming round and formed, so that the yield can be improved. Further, since the material extruded from the forming round due to the different materials of the material and the dummy metal is naturally separated from the dummy metal and taken out, seizure can be prevented.

Furthermore, by repeating the molding while leaving the dummy metal in the narrowed portion, the strength of the tip portion of the molded product is enhanced, it is possible to prevent molding defects due to cracks and the like, and the unusable portion of the tip portion. Can be shortened and the yield can be further improved.

[Brief description of drawings]

1 and 2 are explanatory views for explaining the first embodiment of the present invention, and FIGS. 3 and 4 are explanatory views for explaining the second embodiment of the present invention. 5 to 7 are explanatory views for explaining a conventional hot extrusion molding method.

Claims (2)

(57) [Claims] 1. In extrusion molding of an Al-based rapidly solidified powder alloy, a dummy metal different from the material is provided at an end of a material made of the Al-based rapidly solidified powder alloy, and the material and the dummy metal are separated from each other. In the heated state, the material is pressed through the dummy metal, and is extruded from the molding round through the narrowed portion that is narrowed in the pressing direction to be molded, and only the dummy metal is left in the narrowed portion after the molding. Method for hot extrusion of Al-based rapidly solidified powder alloys characterized by. 2. The hot extrusion molding method for an Al-based rapidly solidified powder alloy according to claim 1, wherein the molding is performed again with the dummy metal left in the narrowed portion after the molding.