JPS6070143A - Manufacture of alloy - Google Patents

Abstract

PURPOSE:To obtain an alloy having a uniform structure by preheating a porous body of the 1st metal in a specified molten metal and infiltrating a melt of the 2nd metal having a lower m.p. than the 1st metal into the porous body under pressure to diffuse well both the metals. CONSTITUTION:Powder of the 1st metal sush as pure Ti is filled into a cylindrical recess defined by the body 2 of a compression molding tool and an under punch 4, and the powder is compressed with an upper punch 3 to form a cylindrical porous molded body 5. This body 5 is heated in a melt of a metal having the practically same composition as the 2nd metal, e.g., molten pure Mg. By the heating the oxidation of the surface of the pure Ti powder forming the body 5 is prevented, so the wetting property to molten metal is not deteriorated. The heated body 5 is set in a preheated casting mold 7. A melt 8 of the 2nd metal such as pure Mg is then charged into the mold 7, pressurized with a plunger 9, and thoroughly solidified in the state.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to alloys, and more particularly to methods of manufacturing the same.

Prior Art The inventors of the present application have developed the present invention in view of various problems in conventional methods of manufacturing alloys by adding and mixing molten metals or powders of other alloying elements to molten metals of alloying elements and sintering methods. Patent application No. 58-13818 filed by the same applicant as the applicant
In item 'O', a method for producing an alloy consisting of a first metal and a second metal having a melting point lower than that of the second metal, forming a porous body consisting of the first metal. , placing the porous body in a mold, pouring a molten metal of the second metal into the mold, and allowing the molten metal to permeate into the porous body, thereby forming the first metal and the second metal. We have proposed a method for manufacturing an alloy, characterized in that the second metal is alloyed with the second metal and the second metal is substantially not present alone in the region of the porous body. In the method for manufacturing the alloy according to the proposal, in order to allow the molten metal of the second metal to penetrate well into the porous body, it is desirable that the porous body be preheated to a temperature higher than room temperature. Conventionally, it has been common practice to heat a porous body sufficiently outside the mold and quickly place it inside the mold.

However, in such conventional alloy manufacturing methods, when a porous body is preheated in an atmosphere containing oxygen such as the atmosphere,
The surface of the first metal powder, etc. constituting the porous body is oxidized, and the wettability of the second metal, such as the first metal powder, to the molten metal is deteriorated due to the oxide film. It is difficult for the molten metal of the second metal to penetrate well into the porous body, resulting in areas with poor penetration, and the molten metal of the second metal is put under high pressure to ensure that the molten metal of the second metal penetrates into the porous body. Therefore, if the molten metal preferentially enters the porous body from the relatively weaker parts, cracks or macro segregation may occur in the produced alloy. There is also a problem that the oxide film formed on the surface of the first metal powder etc. inhibits the mutual diffusion of the first metal and the second metal.
There is a problem in that it is difficult to produce an alloy with a desired structure in which the first metal and the second metal are well diffused.

Purpose of the Invention In view of the above-mentioned problems in the previously proposed method for manufacturing an alloy in which a porous body is preheated, the present invention provides an improved method for manufacturing an alloy so that such problems do not occur. is intended to provide.

According to the present invention, a method for producing an alloy consisting of a first metal and a second metal having a lower melting point than the first metal, forming a porous body made of a metal, heating the porous body in a molten metal of a metal having substantially the same composition as the second metal, placing the porous body in a mold, and A method for producing an alloy is achieved in which the first metal and the second metal are alloyed by pouring a molten metal of the second metal into a mold and allowing the molten metal to permeate into the porous body. Ru.

Functions and Effects of the Invention According to the present invention, the porous body made of the first metal is heated in a molten metal of a metal having substantially the same composition as the second metal, so that the porous body forms a porous body. It is possible to avoid the formation of an oxide film on the surface of the first metal powder, etc., and as a result, the molten metal of the second metal can be made porous without pressurizing the molten metal of the second metal at high pressure. As a result, it is possible to produce an alloy with a uniform structure in which the first metal and the second metal are well diffused into each other without cracking or macro-segregation.

In addition, the porous body made of the first metal in the method for producing an alloy according to the present invention is a powder, discontinuous! Compression molded products such as Li strings, chips or mixtures thereof, continuous fiber bundles, foils,
It may be a laminate of thin plates or the like.

Further, the first and second metals may be a single metal element or an alloy.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be explained in detail below by way of example embodiments with reference to the accompanying figures.

Example 1 First, as shown in FIG. 1, a compression mold consisting of a mold body 2 having a cylindrical hole 1, an upper punch 3 and a lower punch 4 that fit into the hole 7L1 was prepared. Then the first
As shown in the figure, 6.9 g of pure titanium powder with an average particle size of 40 μm is filled into the cylindrical depression defined by the mold body 2 and the lower punch 4, and the hole 1 is filled with 6.9 g of pure titanium powder with an average particle size of 40 μm. The upper punch 3 is fitted, and the pure titanium powder is compressed by pressing the upper punch 3 in a direction approaching the lower punch 4 using a press device (not shown in the figure), whereby the bulk density is 2.279/cc. Diameter 18+nm, length 1211
A cylindrical compression molded body 5 of 1111 was formed.

Next, although not shown in the figure, the compression molded body 5 is dried 170.
It is heated by immersing it in a pure magnesium molten metal at 0'C for 0.5 hours, and then the heated compression molded body 5 is placed in a mold γ at 250°C, and 2
5'Occ, pour pure magnesium molten metal 8 with a water temperature of 700℃, and pour the molten metal into 5'O'OkO by plunge v9.
/ CnQ, and the pressurized state was maintained until the molten metal completely solidified. After the molten metal has completely solidified,
The solidified body was taken out from inside the mold using the knockout bottle 10.

Figure 3 shows a cross section of the Hi-Ma gold alloy produced as described above (
This is an optical micrograph showing a cross section centered at a portion 5 mm from the end face of the original compression molded body and 1 mm from the cylindrical side face at 16-00 times magnification. In addition, FIG. 4 shows a comparative example of Ti- This is an optical micrograph showing the cross section of M (1 alloy) at 100 times magnification. From these figures 3 and 4, it can be seen that in the comparative example Tt-M (+ alloy, the penetration of molten pure magnesium Macro-segregation of Ti-rich (dark areas in Figure 4), which is presumed to be caused by insufficient titanium and magnesium, occurs, and the structure is relatively coarse (titanium and magnesium (This is presumed to be due to insufficient interdiffusion with It can be seen that this alloy has a uniform and fine structure.As a result of analysis by EPM△, it is shown in Fig. 4 of the Ti-M(] alloy manufactured in the comparative example that 1= The oxygen content of the portion shown in FIG. 3 of the Ti-Mo alloy of Example 1 was
The oxygen content of the original compression molded body (2.2 wt%
) was found to be substantially the same value.

Further, FIGS. 5 and 6 are stereoscopic photographs showing central cross sections of solidified bodies containing Ti-Mo alloys manufactured in the above-mentioned Example 1 and Comparative Example, respectively, at 3 times magnification. In these figures 5 and 6, a is Ti-M! II alloy part,
b indicates the M(+rich l-i-M(1) alloy part formed by the diffusion of titanium into the magnesium molten metal, and C indicates the other part, which is substantially only magnesium. .

From these Figures 5 and 6, cracks occur in the alloy of Comparative Example (the white linear portion in Figure 6), whereas in the alloy of Example 1, cracks occur. No defects such as cracks occurred, and it can be seen that this alloy has a uniform structure. Note that the Ti-t produced in this Example 1
The macroscopic composition of the VH1 alloy was Ti-27, 7% M (+).

Example 2 First, in the same manner as in Example 1 above, pure copper powder of 16.34I with an average particle size of 60 μm was formed into a circle with a diameter IBn+m and a height of 12 mm at a bulk density of 5.369/CO. It was formed into a columnar compression molded body. The compression molded body was then heated by immersing it in molten tin at 3'O'O°C for 0.5 hours, and then the heated compression molded body was placed in a mold at 150°C and the molded body was heated. 2 in the mold
A pure tin molten metal with a 5'0CCX water temperature of 350°C was poured, the molten metal was pressurized at a pressure of 1'O'O'Okg/♂, and the pressurized state was maintained until the molten metal completely solidified. After the molten metal was completely solidified, the solidified material was removed from the mold using a knockout bottle.

For comparison purposes, a solidified body containing a Cu-3n alloy was produced in the same manner and under the same conditions as in Example 2 above, except that the compression molded body was heated to 300°C in the atmosphere. formed a body. When these coagulated bodies were cut at the center cross section and the cross sections were observed using an optical microscope, we found that
In the alloy of the comparative example, many cracks, poor penetration of the molten tin, and macro segregation occurred, whereas in the alloy part of the solidified body formed in the above-mentioned Example 9-2, No defects such as cracks occurred, and it was confirmed that this alloy had a uniform structure. Furthermore, the C produced in this Example 2
The macro silk of the U-3n alloy is Cu-35, 3% Sn, and as a result of EMPA analysis, the oxygen content of the surface layer of the Cl1-8n alloy produced in the comparative example was 8.7wt.
%, whereas the oxygen content in the surface layer of the Cu-3n alloy of Example 2 was the oxygen content of the original compression molded body ('0.5
wt%).

Example 3 First, in the same manner as in Example 1 above (e), 15.3 (l) of pure chromium powder with an average particle size of 2 μm was mixed with a bulk density of 5.03 g/cc and a diameter of 18 uun, length 12+
It was formed into a cylindrical compression molded body with a diameter of 100 nm. Next, the compression molded body was placed in a pure aluminum molten metal with a water temperature of 70°C.
．． heating by soaking for 5 hours, then placing the thus heated compression molded body in a mold at 250°C,
25'OCC within the mold.

Pour pure aluminum molten metal at 8'0'O'C into hot water, and use a plunger to pump the molten metal to 5'O'Ok (1/ al
Pressure was applied at a pressure of 1', and the pressurized state was maintained until the molten metal completely solidified. After the molten metal was completely solidified, the solidified body was taken out from the mold using a plunger.

For the purpose of comparison, the solidified body containing the 0r-A1 alloy was manufactured in the same manner and under the same conditions as in Example 3 above, except that the compression molded body was heated to 700°C in the atmosphere. formed a body. When these coagulated bodies were cut at the center cross section and the cross sections were observed using an optical microscope, we found that
In the alloy of the comparative example, many cracks and areas with poor penetration of the molten aluminum occurred, whereas there were no defects such as cracks in the alloy part of the solidified body formed in the above-mentioned Example 3. This alloy was found to have a uniform structure. Furthermore, the 0r- manufactured in this Example 3
The macroscopic quaternary element of the A1 alloy is 0r-13.9%△1, and the oxygen content in the surface layer of the Cr-Al alloy produced in the comparative example is 15.2 wt%. The oxygen content of the surface layer of the Or -A1 alloy of Example 3 is the same as that of the original compression molded product! (1.7 wt%).

Although the present invention has been described above in detail with reference to several embodiments, the present invention is not limited to these embodiments, and various embodiments are possible within the scope of the present invention. This will be clear to those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing a compression mold, FIG. 2 is a melting process showing the alloying process, and FIGS. 3 and 4 are Ti- Optical micrographs showing the cross section of the Mo alloy at 1'O'O magnification, Figures 5 and 6 are the center of the solidified body containing the Ti-MO alloy formed in Example 1 and its comparative example, respectively. This is a stereoscopic photograph of the cross section at 3x magnification. 1...hole, 2...mold body, 3...upper bump,
4... Lower punch, 5... Compression molded body, 7... Mold, 8... Molten metal, 9... Plunger, 10... Knockout bottle Figure 3 Figure 4 Figure 5 Figure (X' 3) Figure 6 261- (x3)

Claims (1)

[Claims] A method for producing an alloy comprising a first metal and a second metal having a melting point lower than that of the first metal, the method comprising: forming a porous body made of the first metal; The porous body is heated in a molten metal having substantially the same composition as the second metal, the porous body is placed in a mold, the molten metal is poured into the mold, and the molten metal is heated. A method for producing an alloy, which comprises alloying the first metal and the second metal by infiltrating the porous body.