JPH08174290A - Partially solidified working method using difference in temperature of solidus - Google Patents

Abstract

PURPOSE: To prevent the wear, the gnawing, etc., of a die in a partially solidified working method, moreover, to prevent a loss caused by a splashed material. CONSTITUTION: In a method for pressure-forming a preform 1 in its partially solidified temperature area by placing the preform 1 in a die 2, which is obtained by preforming mixed powder including metal powder, after placing the preform in the die through a metallic sealing material 4 whose temperature of a solidus is higher than that of the preform 1 by at least 50 deg. or over between the inside surfaces of the die, pressure-forming is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forming method utilizing a semi-molten state of a material, and is applied to, for example, production of an aluminum-based composite disk rotor obtained from a mixed powder of aluminum alloy powder and ceramic powder as a raw material. To be done.

[0002]

2. Description of the Related Art In the semi-melt processing method, a raw material obtained by preforming a mixed powder containing a metal powder as a raw material produces a liquid phase in the raw material. Plastic working is performed in the semi-melting temperature range, which is the temperature range.
For example, when a disk rotor for a vehicle brake is manufactured with a mixed powder of aluminum alloy powder and ceramics powder, according to the semi-melt press working method among the above-mentioned semi-melt working methods, a raw material obtained by pre-forming this mixed powder is formed. It is placed in a mold, heated to a semi-melting temperature range of the aluminum alloy, and pressure-molded.

However, if the raw material is heated and held in the mold in the semi-melting temperature range and pressure-molded in the mold, the generated liquid phase is scattered and the raw material material is lost. Is difficult to obtain. Further, in the above-mentioned semi-melt press working method, the die temperature reaches the solidus temperature of the base material, so that even if the die material is SKD material which is hot die steel, the hardness decreases and the die There is also a problem that galling is likely to occur on the inner surface due to the work material.

[0004]

SUMMARY OF THE INVENTION The present invention prevents these problems in the semi-melt processing method, that is, the wear of the mold and the scattering loss of the liquid phase. In a method of placing a material in a mold and press-molding the raw material in the semi-melting temperature range, the solidus temperature is at least 50 degrees higher (preferably 70 to 90 degrees) higher than that of the raw material. A semi-melt processing method utilizing a solidus temperature difference, characterized in that the raw material is placed in the mold via a metal sealant between the inner surface of the mold and pressure molding. .

[0005]

In the semi-melt press working of the above aluminum-based composite disk rotor, solid lubricants such as graphite and molybdenum disulfide are generally used for preventing galling of the mold. However, in this case the semi-melt processing temperature is 500-66.
Due to the high temperature of 0 ° C., the above solid lubricant did not exhibit a sufficient anti-galling effect.

Therefore, in the present invention, a material having a solidus temperature higher than that of the preformed raw material, that is, a material having a solidus temperature higher than the semi-melting temperature range of the raw material is used as the sealing material. By interposing between the profile and the inner surface of the mold, when the profile is pressure-molded in the semi-melting temperature range, a liquid phase is generated in the profile, but the sealing material Since the solid phase is always in the solid state, the defect that the liquid phase of the raw material adheres to the mold is eliminated.

Furthermore, since this sealing material has a solidus temperature higher than that of the molding material by 50 ° C. or more, it does not melt during the semi-melt processing of the molding material but is in a softened state, and the sealing material is compressed. The strength is negligible and the loss of molding pressure is negligible. Further, since the material and the sealing material are molded in a predetermined shape in advance, the productivity is greatly improved.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. Aluminum alloy with excellent heat resistance (Al-8wt% F
e, solidus temperature: 653 ° C) Prepare a mixed powder in which 30% by weight of alumina particles is added to the powder, and the mixed powder is molded at
A columnar shaped material was obtained by press preforming at 200 ° C. and a pressure of 300 MPa. The outer diameter of this base material is uniformly 1 mm smaller than the inner diameter of the base material accommodating circular hole of the mold for semi-melt press molding described below by 1 mm.

As shown in FIG. 1, the base material (1) is placed on the lower pressure punch (3) in the base material accommodating circular hole of the mold for semi-melt press molding (2). And a cylindrical phosphor copper alloy seal having a thickness of less than 1 mm and a height twice the thickness of the blank (1) in the gap between the blank (1) and the inner surface of the mold (2). Material (4) (solidus temperature: 730 ° C.) was charged.

Next, the upper pressure punch (5) is set,
After applying a pressure of 100 MPa by the upper and lower pressure punches (3) and (5), the aluminum alloy of the raw material (1) was heated and maintained at 650 ° C. which is a semi-melting temperature. After holding for a predetermined time,
The pressure was further increased to 200 MPa to perform semi-melt press molding, the mold was taken out from the mold, and after cooling, the sealing material (4) was removed by machining to obtain a molded body (6). After that, the inner surface of the mold (2) was examined in detail, but there was no scratch such as galling. In addition, there was no material loss of the raw material.

[0011]

As described above, according to the present invention, in the semi-melt processing method, there is no loss due to the dissipation of the raw material material, and further, there is no scratch or abrasion of the metal mold and the like, and the life is extended, so that the cost can be reduced. As a result, it is possible to improve productivity in manufacturing an aluminum-based composite disc rotor and the like, which is a significant effect.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Form material 2 Semi-melt press molding die 3 Lower pressure punch 4 Seal material 5 Upper pressure punch 6 Molded body

Claims (2)

[Claims] 1. A method of placing a preform, in which a mixed powder containing a metal powder is preformed, in a mold, and press-molding the preform in a semi-melting temperature range thereof. A solidus temperature difference characterized in that the metal seal material having a high phase line temperature of at least 50 ° C. or higher is placed between the mold material and the mold material and then pressure-molded. Semi-melt processing method using. 2. The solidus temperature of the metal seal material is 70 to 90 degrees higher than the solidus temperature of the matrix material.
The semi-melt processing method described in.