JPH0598307A - Method for shaping metal mixture - Google Patents

Abstract

PURPOSE:To work a mixture of the lightweight Al-based powder excellent in workability and the metal powder of Fe, Ti, etc., having high strength, heat resistance, magnetism, corrosion resistance, etc., into a shape approximating that of a member to be used with good operability and to produce the metal powder useful especially in forming a valve material for the automobile. CONSTITUTION:The powder of Al or Al alloy contg. 25-75wt.% Al and the powder of other metal and alloy are mixed and solidified to obtain a mixture (Al-50Fe-3Ni, Al-50Ti, etc.), the mixture is extrusion-forged at <=560 deg.C and 5-130mm/s stripping (punch) rate in a metallic die with the ratio of the bearing length 1 to the die 4 controlled to 30-80%, the radius of curvature 2 on the die outlet side to 15-70% and the diameter 3 of the back hole of the die to 102-110%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a mixture of Al-based powder, which is lightweight and excellent in workability, and other metal-based powder having high strength, heat resistance, magnetism, corrosion resistance, etc. The present invention relates to a processing method, and more particularly, to a method for shaping a metal mixture useful for forming a valve material for automobiles.

[0002]

2. Description of the Related Art As the weight of automobiles tends to be reduced, Al of each member
However, as the demands for heat resistance and other properties increase, the Al mixture is promising as a lightweight and high-strength heat resistant material. For this kind of mixture, for example, magnetic Al in which Al and Fe are mixed is known. In general, although Fe, Ti, etc. are superior in strength and heat resistance to Al, when they are made into an Al mixture due to their large density, they are more difficult to process than Al alloys, and conventional wrought technology does not produce a product. There is a problem that it cannot be plastically processed into a close shape.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have found that it is suitable to apply extrusion forging in order to form an Al mixture into a target shape with almost no cutting,
The optimum conditions were examined. Specifically, it was an object to obtain a valve-like shape by extrusion forging of a mixture of Al or Al alloy powder and Fe powder or Ti powder and extrusion forging, similar to general Al alloy processing.
In order to further improve mass productivity, it was considered to extrude a large Al mixture (billet) and then perform extrusion forging after extrusion, but in this case, the deformation resistance of the mixture increases due to work hardening by extrusion, It was clarified that it is necessary to consider the conditions and mold shape. That is, if the resistance during extrusion forging becomes large, it causes clogging, and it is necessary to define the mold shape in order to reduce the resistance. However, if the back hole diameter of the mold is large even if the resistance is low, there is a problem that the extruded portion is bent.

In order to solve these problems, the present invention has been developed as a result of intensive research on extrusion forging conditions and die shape. The purpose of the present invention is to make a metal mixture light in weight, high in strength and high in heat resistance. The object of the present invention is to provide a shape-imparting method capable of smoothly extruding and forging as a predetermined shape member. In addition, according to the present invention, for example, the material of aluminide as disclosed in Japanese Patent No. 15479848 can be applied.

[0005]

In order to achieve the above-mentioned object, a method for imparting a shape to a metal mixture according to the present invention is a method of forming an Al or Al alloy powder having an Al content of 25 to 75 at% and another metal or alloy powder. In the method of extrusion forging a mixed and solidified mixture to give a predetermined shape, the conditions of extrusion forging are a temperature of 560 ° C. or less and an extrusion (punch) speed of 5 to 130 mm / s.
And, the bearing length of the forging die is 30 to the die diameter.
80%, the radius of curvature of the die exit side of the forging die is 15 to 70% of the die diameter, and the die back hole diameter of the forging die is 1 of the die diameter.
The characteristic feature of the configuration is to set it to 02 to 110%.

[0006] Of the above-mentioned structure, a specific portion relating to the shape of the forging die is shown in Fig. 1 (overall longitudinal sectional view of the forging die), 1 is a bearing length, 2 is a radius of curvature on the die exit side,
3 is the die back hole diameter. Then, the bearing length 1 is 30 to 80% of the die diameter 4, the radius 2 of the die exit side is 15 to 70% of the die diameter 4, and the die back hole diameter 3 is 102 to 110% of the die diameter 4. To be set.

In the constitution of the present invention, the requirement that the Al composition in the mixture is limited to 25 to 75 at% is a prerequisite for the mixture to have characteristics such as lightness and heat resistance. The amount of Al is 25 at%. If it is less than 75% by weight, the workability is lowered and the effect of weight reduction is reduced. On the other hand, if it exceeds 75% by weight, properties such as heat resistance are not sufficiently imparted.

Of the extrusion forging conditions, the forging temperature is 560
The temperature is set to ℃ or lower because the deformation resistance during extrusion forging decreases when the temperature exceeds 560 ℃, and it becomes difficult to control the extrusion speed and the like, and structural defects such as vertical streaks occur in the extrusion forged material. is there. Further, in some cases, the extrusion forged material may be oxidized. Extrusion (punch) speed of extrusion forging is 5 to 130
The reason why it is set to mm / s is that if it is less than 5 mm / s, the productivity becomes low, and if it exceeds 130 mm / s, defects such as vertical streaks occur in the extruded forged material.

When the bearing length with respect to the die diameter is less than 30% and the radius of curvature on the die exit side is less than 15% among the setting requirements relating to the die shape, the resistance becomes low and it becomes difficult to control the extrusion speed. If the bearing length with respect to the diameter exceeds 80% and the radius of curvature on the die exit side exceeds 70%, the resistance becomes large, resulting in the occurrence of pressing clogging. Also, the diameter of the back hole of the die is 10 with respect to the diameter of the die.
If it is less than 2%, the resistance will be high and clogging will occur,
When it exceeds 110%, bending occurs in the extruded portion.

Therefore, in the present invention, a mixed powder of Al or Al alloy having the above composition and another metal or its alloy is extruded to form a mixture, and then extrusion forged under the conditions satisfying all the above requirements. As a result, a member having light weight, high strength, and heat resistance, which is always free of tissue defects and has appropriate extrusion resistance, is molded into a predetermined shape.

[0011]

According to the present invention, the composition of the metal mixture as an extrusion forging material has an Al content of 25 to 75 wt% to impart a lightweight property and excellent strength and heat resistance to the material. By setting the forging temperature and the extrusion speed within a specific range, it is possible to give an extrusion condition that does not cause structural defects such as vertical streaks, and further by specifying the die shape, it is possible to control to an appropriate extrusion speed.

[0012] By virtue of such effects, it becomes possible to mass-produce a member having a predetermined shape through a smooth working process.

[0013]

EXAMPLES Examples of the present invention will be described below in comparison with comparative examples. Examples 1-2, Comparative Examples 1-2 Al-50 at% Fe-3 at% Ni
Mix Ni alloy powder and Fe powder, put in Al can, and
After degassing (10 ^-3 Torr or less) at 00 ° C for 5 hours, the diameter was changed from 10 inches to 70 inches at 400 ° C (reduction rate of cross section 92
%) Extruded. 64 inches in diameter and 5 height from this push rod
A 0-inch extrusion forging material was cut out, and extrusion forging was performed while changing the forging conditions and the die shape. The results are shown in Table 1 in comparison with forging conditions and die shapes. The extruded forged material of the example had a good material structure, but the material of the comparative example had vertical streaks.

[0014]

Examples 3 to 4, Comparative Examples 3 to 8 Al powder and Ti powder were mixed so as to have Al-50 at% Ti, placed in an Al can, and degassed (400 ° C x 5 hours) (10
^-3 Torr or less), then at 400 ° C, diameter 8 inches to diameter 40
It was extruded to an inch (area reduction of 96%). A material for extrusion forging having a diameter of 30 inches and a height of 25 inches was cut out from this extrusion rod, and extrusion forging was performed while changing the forging conditions and the shape of the die. The results are shown in Table 2 in comparison with forging conditions and die shapes. As shown in the results of Table 2, the material structure of the extruded forged material according to the example was good, but the material of the comparative example had defects such as vertical streaks and extrusion clogging.

[0016]

[0017]

As described above, according to the present invention, a mixture of an Al-based metal which is lightweight and excellent in workability and another metal which is excellent in strength, heat resistance, magnetism and corrosion resistance is smoothly used by extrusion forging. It can be molded into a shape similar to a member. Therefore, for example, it is useful for the purpose of mass-producing valve members for automobiles with good operability.

[Brief description of drawings]

FIG. 1 is an explanatory longitudinal sectional view illustrating an extrusion casting mold used in the present invention.

[Explanation of symbols]

 1 Bearing length 2 Radius of die exit side radius 3 Die back hole diameter 4 Die diameter

Claims (1)

[Claims] 1. An Al or A having an Al content of 25 to 75 at%.
In a method of extruding and forging a mixture obtained by mixing and solidifying an alloy powder and another metal or an alloy powder, a condition of extrusion forging is a temperature of 560 ° C. or less, an extrusion (punch) speed is 5 to 130 mm / s, and the bearing length of the forging die is 30 to 80% of the die diameter, the radius of curvature of the die output side of the forging die is 15 to 70% of the die diameter, and the die back hole diameter of the forging die is 102 of the die diameter. A method for imparting a shape to a metal mixture, which is set to 110%.