JPH1030102A - Method for extrusion-forming powdery metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion-forming method of powdery metal which can economically produce a high quality shape material with nearly no mixed sheath material in the obtd. shape material, in the improvement of the extrusion- forming method producing the shape material from the powdery metal. SOLUTION: This forming method to obtain the formed material comprises sealing a formed material 9 obtd. by compression of the powdery metal into the sheath 8 to form a billet 7, incorporating this billet 7 into a container 2 having a die 1 for forming, pressing the billet 7 with a dummy block 5 and extruding the formed material 9 from the die 1. In such a case, a dummy body 6 as the separated body formed with almost the same material as the metal- made sheath 8 is interposed between the billet 7 and the dummy block 5 and the billet 7 is pressed through the dummy body 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an extrusion method capable of efficiently producing a long mold from powder metal.

[0002]

2. Description of the Related Art Conventionally, when a long bar or a mold made of metal having good ductility is manufactured, a method of extrusion molding has been adopted. By such an extrusion method,
When it is desired to manufacture a mold made of a material having difficulty in processing, for example, a metal composite material, for example, as shown in FIG. 4, the material is heated as needed in a container b connected to the tip of a die a. inserting the billet c, and the die hole a ₁ dice a to extrude metallic material by pressurizing the dummy block d from the rear, there is a so-called forward extrusion process.

A billet c is placed in a cylindrical metal sheath e.
It is filled with unformed powder or a columnar molded body f obtained by pressing, and the same as the sheath e between the billet c and the dummy block d in order to prevent the molded body f from being left behind. dummy portion e ₁ of the material of the wall thickness are provided.

However, when hot extrusion is actually performed,
As shown in FIG. 5, the rear of the resulting mold member g, dummy portion e ₁ is because, causes deep entered in the form, such as the core material, portions where the dummy portion e ₁ has penetrated can not be used as a product, waste There is a problem that the yield of the product is reduced due to the occurrence of.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above problems, and there is almost no mixing of a sheath material constituting a billet into a mold material obtained by extrusion molding. It is an object of the present invention to provide a method for extruding powder metal, which can improve the yield and economically produce a high-quality mold material.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention relates to a method for forming a billet by molding a compact obtained by compressing powdered metal into a cylindrical metal sheath. A method for extruding a compact from a die by accommodating the billet in a container having a die and pressing the billet through a dummy block to obtain a mold material, wherein the billet and the dummy block are extruded. And a separate dummy body made of substantially the same material as the metal sheath is interposed between them, and the billet is pressed through the dummy body by pressing a dummy block to form the molded body. It is characterized by being extruded from the die.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for extruding powder metal of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a state before operation of an apparatus A for performing the powder metal extrusion molding method of the present invention. Apparatus A comprises a cylindrical container 2 above a die 1 for extruding powdered metal. The die 1 has a rectangular die hole 1a and the die hole 1a.
And is supported by a die holder 3 so as to be connected to the lower end of the container 2.

A punch 4 is mounted on the upper part of the container 2 so as to be able to move up and down, and presses a billet 7 housed in the container 2 via a dummy block 5 and a dummy body 6. Here, the billet 7 is formed by vacuum-filling a cylindrical molded body 9 obtained by press-molding and heat-sintering powdered metal in a cylindrical metal sheath 8.

The sheath 8 is formed by forming a thin metal plate into a cylindrical shape. For example, when the molded body 10 is made of copper (Cu) powder and alumina (Al ₂ O ₃ ) powder, And the copper (Cu) so as to cover the entire billet 7 with substantially the same thickness. Dummy body 6
Is copper (C), which is substantially the same material as the sheath 8 of the billet 7.
u), and is formed in a cylindrical truncated shape, and its thickness (height) is set to about １ ／ of the inner diameter of the container 2.

Next, the step of extruding the molded body 9 using the above-described apparatus A will be described. First, when the punch 4 is lowered and the dummy block 5 is pressed, the billet 7 is pressed from above to the die 1 via the dummy body 6. When the billet 7 is pressed toward the die 1, the molded body 9 is compressed downward and integrated with the sheath 8. The integrated billet 7 enters the approach section 1b and is squeezed,
As shown in FIG. 2, the die 10 is extruded from the die hole 1a to the outside.

In this step, the billet 7 is about 900
The temperature of the dummy body 6 is maintained at the same temperature as the container 2 and the die 1, that is, about 300 ° C. Therefore, there is no phenomenon that the dummy part f ₁ of the conventional sheath f shown in FIG. 5 from entering a shape such as the core material, as shown in FIG. 3, the sheath 8 to the rear end 10a of the mold member 10 and the dummy member 6 (Cu) is slightly mixed in the extruded mold material 10, and the product yield is improved.

[0012]

According to the present invention, the billet is extruded through a separate dummy body made of the same material as the sheath of the billet accommodating the molded body made of powdered metal. Almost no mixing of the material of the dummy body with the mold material obtained through the extrusion process is seen, and wasteful parts are drastically reduced, so the product yield is remarkably improved and high quality mold material can be economically manufactured. It has advantages such as

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state before operation of an apparatus for performing a powder metal extrusion molding method of the present invention.

FIG. 2 is an explanatory view showing a step of forming a mold using the apparatus of FIG. 1;

FIG. 3 is a longitudinal sectional view showing a mold obtained through the process of FIG. 2;

FIG. 4 is a sectional view of a conventional apparatus for extruding powder metal.

FIG. 5 is a sectional view showing a mold formed by the apparatus shown in FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Die 2 Container 5 Dummy block 6 Dummy body 7 Billet 8 Sheath 9 Molded body 10 Mold material

Claims (1)

[Claims] 1. A billet is formed by enclosing a compact obtained by compressing powdered metal in a cylindrical metal sheath, and the billet is accommodated in a container having a molding die, and the billet is inserted through a dummy block. A method for extruding the molded body from the die by pressing the billet to obtain a mold material, the method comprising: extruding a molding material between the billet and the dummy block using substantially the same material as the metal sheath. Extruding the molded body from the die by interposing a separate dummy body and pressing the billet through the dummy body by pressing a dummy block. .