JPS6070140A - Manufacture of alloy - Google Patents

Abstract

PURPOSE:To obtain an alloy having a uniform composition and structure free from crack and macro-segregation by binding powder or the like forming a porous molded body of the 1st metal with an inorg. binder and by infiltrating a melt of the 2nd metal having a lower m.p. than the 1st metal into the molded body under pressure. CONSTITUTION:Powder, shavings, foil, sheets, fibers or fine wires of the 1st metal or a mixture thereof, e.g., pure Cr powder is mixed with an inorg. binder such as an aqueous soln. of sodium silicate. The liq. mixture is filled into a square pillar-shaped recess defined by the body 4 of a compression molding tool and an under punch 6, and the mixture is compressed with an upper punch 5 and dried to form a rectangular prism-shaped molded body 7. This body 7 is preheated and set in a preheated casting mold 8. Molten pure Al 9 is then charged into the mold 8, pressurized with a plunger 10, 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 alloys.

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 No. 0, a method for producing an alloy consisting of a first metal and a second metal having a lower melting point than the second metal,
forming a porous body made of the first metal, placing the porous body in a mold, pouring a molten metal of the second metal into the mold, and infiltrating the molten metal into the porous body; alloying the first metal and the second metal by
The present invention has proposed a method for manufacturing an alloy, characterized in that an alloy is formed in which the second metal does not substantially exist alone in the region of the porous body.

In the method for producing an alloy according to the proposal, in order to efficiently produce an alloy with a predetermined uniform composition and structure,
The porous body is formed so that it can maintain a predetermined shape and density even during the process of placing the porous body in a mold and pouring molten metal of the second metal into the mold, and It is desirable to forcibly infiltrate the molten metal of the second metal into the porous body.Therefore, it has conventionally been common practice to compression mold powder of the first metal and use the compression molded body as the porous body1. Further, the molten metal of the second metal is pressurized at a pressure of about 500 to 1000 k (1/ca').

However, in such conventional alloy manufacturing methods, it is difficult to form a compression molded body with uniform density by compression molding, and the compression molded body has parts that are relatively weak in strength compared to the other parts. Therefore, when the molten metal of the second metal is pressurized, the molten metal preferentially invades the comparatively weaker parts of the compact, resulting in cracks and macro-segregation in the produced alloy. The problem is that it can sometimes happen.

In addition, when forming a compression molded body as a porous body by compression molding, it is difficult to form a compression molded body with a small apparent density such as powder of the first metal. There is a problem in that the composition and structure are limited by the size of the first metal powder, etc. Furthermore, when the porous body is composed of foil, thin plate, fiber, thin wire, etc., it is necessary to ensure that the porous body maintains a predetermined state even during the process of pouring the molten metal of the second metal into the mold. The problem is that it is difficult to do so.

OBJECTS OF THE INVENTION In view of the above-mentioned problems in the previously proposed method for manufacturing an alloy, it is an object of the present invention to provide a method for manufacturing an alloy that is improved so that such problems do not occur.

According to the present invention, the present invention provides 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. , chips, foil,
A porous molded body made of a thin plate, fiber, thin wire, or a mixture thereof, in which individual powders are bonded together with an inorganic binder, the molded body is placed in a mold, and the mold is This is achieved by an alloy manufacturing method in which the first metal and the second metal are alloyed by pouring a molten metal of the second metal into the molded body and allowing the molten metal to permeate into the molded body.

Functions and Effects of the Invention According to the present invention, the porous molded body made of the powder of the first metal, etc. has no weak parts that allow the molten metal of the second metal to penetrate preferentially. Since it is formed with a structure in which individual powders, etc. are bonded together with an inorganic binder, the molten metal of the second metal can be well and evenly penetrated into the molded body. An alloy with a uniform composition and structure without cracking or macro segregation even when a square meter of metal is pressurized! ! ! can be built.

Furthermore, the inorganic binder used in the method for producing the alloy according to the present invention is stable even at high temperatures, and even if it remains in the alloy, it will not have a substantial adverse effect on the properties of the alloy. The binder is preferably a binder that does not inhibit mutual diffusion between the first metal and the second metal, such as sodium silicate (Na20-S102, N) which solidifies as silica (Slop) by drying. al!
O-S 102 9 120], colloidal silica, ethyl silicate [(C2Ha)4Si0
4) and the like are preferred. Further, in the method for producing an alloy according to the present invention, the porous molded body made of the first metal is a compression molded body of powder, discontinuous fibers, chips, or a mixture thereof, a bundle of continuous fibers, It may be a laminate of foils, thin plates, etc., and the first metal and second metal may be either 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.

1" First, as shown in FIG. 1, 368.1 g of paper chromium powder with an average particle size of 2 μm and a sodium silicate aqueous solution of 0°64.12 were mixed into an impeller in a mixing container 1. Mix by rotating 2.

Next, as shown in FIG. 2, a hole 3 with a square cross section is formed.
A compression molding mold consisting of a mold body 4 having a shape, an upper punch 5 and a lower punch 6 that fit into the hole 3 is prepared, and the mold is formed in a rectangular prism-shaped depression defined by the mold body 4 and the lower punch 6 as described above. The upper punch 5 is fitted into the hole 3, and the mixed liquid is compressed by pressing the upper bunch 5 and the lower punch 6 toward each other using a press device (not shown). By drying this, a compression molded body 7 in the shape of a rectangular parallelepiped of 80 x 80 x 20 mm (7) with a bulk density of chromium powder of 2°88 (+/CC) was formed.The silica content of this compression molded body was It was 14vo1% (21'1lft%).

Next, although not shown in the figure, the compression molded body 7 is preheated to 600°C in an argon gas atmosphere, and then the compression molded body 7 is placed in a mold 8 at 250°C as shown in FIG. Then, pour 100Qcc of pure aluminum molten metal 9 at a temperature of 800°C into the mold, and pour the molten metal into the plunger 10.
The molten metal was pressurized at a pressure of 1000 kg/♂, and the pressurized state was maintained until the molten metal completely solidified. After the molten metal was completely solidified, the solidified material was taken out from the mold using a knockout bottle 11.

FIG. 5 is a stereoscopic photograph showing a central cross section of the solidified body containing the Or-A1 alloy produced as described above at 3 times magnification. Further, FIG. 6 shows a solidified body containing a Cr-A1 alloy as a comparative example manufactured in the same manner and under the same conditions as Example 1 above, except that sodium silicate as an inorganic binder was not used. 3 (8) is a stereoscopic photograph showing the central cross-section of A1-rich Cr-Al formed by
C indicates an alloy portion, and C indicates a portion consisting essentially only of aluminum.

From these figures 5 and 6, it can be seen that in the alloy of the comparative example, there are areas with poor penetration of the molten aluminum (1), whereas in the alloy of Example 1, there are areas with poor penetration of the molten metal, etc. No cracking occurred, and it can be seen that this alloy has a uniform structure.
The macroscopic composition of the r-Al alloy was 0r-28, 9%A1.

Example 2 First, in the same manner as in Example 1 above, colloidal silica was used as an inorganic binder and the average particle size was 40.
333.μm. ．． Pure manganese powder of 1 has a bulk density of 2
．． It was formed into a rectangular parallelepiped compression molded body of 80×8OX20 mm at 60 o/cc.

The silica content of this compression molded product is 22.5vol% (
35 wt%). Next, the compression molded body was preheated to 700°C in an argon gas atmosphere, the compression molded body was placed in a mold at 250°C, and 100 OCC was placed in the mold.
A molten metal of pure aluminum at a temperature of 800° C. was poured, and the molten metal was pressurized with a plunger at a pressure of 1000 kg/×9, 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.

FIG. 7 is a stereoscopic photograph showing, at double magnification, the central cross section of the solidified body containing the Mn-Al alloy produced as described above. In this Figure 7, a indicates the Mn-Al alloy part, b indicates the A1-rich 1yln-A1 alloy part formed by the diffusion of manganese into the molten aluminum, and C
1 and 2 respectively indicate portions made essentially only of aluminum.

It can be seen from FIG. 7 that no defects such as cracks occur in the alloy of Example 2, and that this alloy has a uniform structure 9-. The macroscopic composition of the Mn-A1 alloy produced in Example 2 is Mn-28,6.
%A1.

Example 3 In the same manner as in Example 1 above, colloidal silica was used as the inorganic binder and the average fiber diameter was 80 μm.
Cu-zn mH of 105.2 (l) with an average fiber length of 3 mm is
A rectangular compression molded body measuring 0x80x20++m was formed. The silica content of the compression molded product is 16vo+%<
28 wt%). Next, the compression molded body thus formed was preheated to 600°C in an argon gas atmosphere, and then the compression molded body was placed in a mold at 250°C,
A molten aluminum alloy (J■S standard A C4, C) of 1000 cc and a water temperature of 800 ℃ is poured into the mold, and the molten metal is pressurized at a pressure of 1000 ko/♂, and the pressurized state is the molten metal. was held until completely solidified. After the molten metal was completely solidified, the solidified material was taken out from the mold using a knockout pin.

10- FIG. 8 is a stereoscopic photograph showing the center cross section of the solidified body containing the Cu-Zn-A1 alloy manufactured as described above at 2 times magnification. In Fig. 8, a indicates the Cu-Zn-A1 alloy portion, and b indicates the CIJ of the A1 ridge formed by diffusion of copper and zinc into the molten aluminum alloy.
-C indicates a portion made of Zn-A1 alloy, and C indicates a portion made essentially only of aluminum alloy. From FIG. 8, it can be seen that defects such as cracks did not occur in the alloy of Example 3, and this alloy had a uniform I] texture. Furthermore, the CLI-Z manufactured in the above-mentioned Example 3
The macro composition of n-A1 alloy is Al-15゜2%Cu-
It was 10.1% Zn.

Although the present invention has been described above in detail with reference to several embodiments, the present invention is not limited to these embodiments1, and various embodiments are possible within the scope of the present invention. This will be obvious to those skilled in the art.

[Brief explanation of the drawing]

Figure 1 shows the process of mixing powder and inorganic binder, Figure 2 shows the process of solidification, Figure 3 shows the compression molded body, and Figure 4 shows the alloying process. Showing solution, 5th
The figure and FIG. 6 are stereoscopic photographs showing the central cross section of the solidified bodies formed in Example 1 and its comparative example, respectively, at 3x magnification.
FIG. 7 and FIG. 8 show the solidified body containing the Mn-Al alloy and the Cu-
It is a stereoscopic photograph showing a central cross section of a solidified body containing a Zn-A1 alloy at double magnification. 1... Mixing container, 2... Impeller, 3... Hole, 4
... Mold body, 5 ... Upper punch, 6 ... Lower punch, 7 ... Compression molded product, 8 ... Mold, 9 ... Molten metal, 10 ... Plunger, 11 ... Knockout bin Patent applicant: Toyota Motor Corporation Agent: Masaki Akashi, patent attorney Figure 1 Figure 3 Figure 5 Figure 6 Figure 7 (x2) Figure 8 (x2) 243-

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 second metal, the method comprising: powder, chips, bamboo, thin plate, NJA fiber, thin wire of the first metal; Or, a porous molded body made of a mixture thereof, in which individual powders are bonded together with an inorganic binder, the molded body is placed in a mold, and the second molded body is placed in the mold. A method for producing an alloy, which comprises alloying the first metal and the second metal by pouring a molten metal and allowing the molten metal to permeate into the molded body.