JPS6070146A - Manufacture of alloy - Google Patents

Abstract

PURPOSE:To obtain an alloy having a uniform structure free from crack and macro-segregation by preheating a porous body of the 1st metal with hot air introduced into the casting mold of an alloy manufacturing apparatus and by infiltrating a melt of the 2nd metal having a lower m.p. than the 1st metal into the porous body under pressure. CONSTITUTION:Powder of the 1st metal such as pure Mn is compression-molded into a porous columnar body 10, and this body 10 is set in the recess 4a of the drag 3 of an alloy manufacturing apparatus 1 for forming an alloying chamber 4. The cope 2 and the drag 3 are held in a half-opened state, and heated gaseous Ar is introduced into the chamber 4 from the nozzle 17 of a hot air feeder put between the cope 2 and the drag 3 from one end the apparatus 1 to heat the wall of the chamber 4. At this time, the temp. of the hot air is measured with a thermocouple 18 or the like put in the pressurizing chamber 5. The cope 2 and the drag 3 are then held in a fastened state, and a melt 7 of the 2nd metal such as pure Al is introduced into the chamber 5 through a runner 6, 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 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 allowing the molten metal to permeate into the porous body; alloying the first metal and the second metal;
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 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, in the process of placing the preheated porous body in the mold, the porous body is exposed to the outside air and cooled, causing the preheated porous body to cool down. Since the temperature, especially the surface temperature of the tube, decreases, it is difficult to penetrate the molten metal of the second metal into the porous body, and the molten metal has priority over the relatively weaker parts of the porous body. If it penetrates into the alloy, there is a problem that cracks or macro segregation may occur in the manufactured alloy.

In addition, in order to avoid the temperature of the porous body from dropping below the desired temperature, if the preheating temperature of the porous body is set to a relatively high temperature, the temperature of the porous body may be lowered during the process of placing it in the mold. There is a problem in that the first metal constituting the porous body is oxidized by being exposed to outside air.

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. The purpose is to provide.

According to the present invention, the present invention provides 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. Using an alloy manufacturing apparatus having a mold cavity that receives a porous body and a molten metal of the second metal, the porous body is placed in the mold cavity, and hot air is introduced into the mold cavity to remove the porous body. A method for producing an alloy in which the first metal and the second metal are alloyed by heating a mass body, introducing the molten metal into the mold cavity, and allowing the molten metal to permeate into the porous body. achieved by.

Effects and Effects of the Invention According to the present invention, the porous body is heated to a desired temperature in the mold cavity before the molten metal of the second metal is introduced into the mold cavity. Since the wall surface is also heated to a relatively high temperature, the temperature of the porous body is prevented from dropping significantly until the molten metal of the second metal is introduced into the mold cavity. The molten metal of the second metal can satisfactorily penetrate into the porous body, thereby making it possible to produce an alloy with a uniform structure without cracks or macro segregation.

The hot air used to heat the porous body in the method for producing an alloy according to the present invention may be heated air, but especially when the first metal constituting the porous body is at a high temperature. If the element is easily oxidized or the porous material is heated to a relatively high temperature, use a non-oxidizing gas, i.e. a reducing gas such as carbon monoxide or hydrogen, or argon gas or nitrogen gas. Preferably, it is an inert gas such as gas. In addition, the porous body in the method for producing an alloy according to the present invention is a compression molded body of the first metal powder, discontinuous TiA fibers, chips, or a mixture thereof, a bundle of continuous fibers, foil, thin plate, etc. The first and second metals may be a single metal element or an alloy.

5. Description of Embodiments FIGS. 1 and 2 show one alloy manufacturing apparatus suitable for use in carrying out the method for manufacturing an alloy according to the present invention, in the porous body heating process and the alloying process, respectively. FIG. In these figures, 1 indicates an alloy manufacturing apparatus, and the alloy manufacturing apparatus 1 consists of an upper mold 2 and a lower mold 3. These upper and lower molds are assembled to each other in the half-open state shown in FIG. 1 and in the half-open state shown in FIG. tI4 is kept in a straight line state.

Further, these upper and lower molds cooperate with each other to define an alloying chamber 4 and a pressurizing chamber 5.

A runner 6 is formed in the upper mold 2 for injecting a molten metal of the second metal into the pressurizing chamber 5 .

The pressurizing chamber 5 receives a plunger 9 that reciprocates within a cylinder bore 8 formed in the upper mold 2, and the molten metal 7 charged into the pressurizing chamber 5 is pressurized by this plunger. As a result, the porous body 1 charged into the alloying chamber 4
The molten metal of the second metal is allowed to penetrate into each of the small holes of the second metal.

Furthermore, a cylinder bore 11 is formed in the lower die 3 and communicates with the pressurizing chamber 5, and a knockout bottle 12 that reciprocates along the cylinder bore is inserted through the cylinder bore. The two end surfaces of the knockout bottle 12 define the bottom surface of the pressurizing chamber 5. A bore 13 communicating with the alloying chamber 4 of the Nita 1st tank 3
Knockout bins 15 and 16 are provided in the knockout bins 15 and 14 for taking out the solidified material solidified in the alloying chamber 4 from the lower mold 3.
is inserted.

Next, one embodiment of the method for manufacturing an alloy according to the present invention using the alloy manufacturing apparatus configured as described above will be described.

First, pure manganese powder with an average particle size of 40 μm and a bulk density of 3.72 (+/CC) was prepared with a diameter of 241
1I1. , compression molded into a cylindrical body with a length of 601IIIR.

Next, the upper mold 2 is released from the lower mold 3, and the alloying chamber 4 of the lower mold 3 is removed.
The cylindrical body 10 is placed in the depression 4a defining the cylindrical body 10, and the upper mold 2 and the lower mold 3 are held in a half-open state as shown in FIG. 1 by pressure holding means (not shown). A nozzle 17 of a hot air supply device (not shown in the figure) is inserted from one end of the alloy manufacturing apparatus 1 between the upper mold 2 and the lower mold 3, and the alloying chamber 4 is
Argon gas at 600°C at a flow rate of 20J2/win
The temperature of the wall surface of the cylindrical body 10 and the alloying chamber 4 was heated to about 600° C. and about 400° C., respectively, for 2 minutes. In this case, the other end of the alloying chamber 4 or the pressurizing chamber 5
By inserting a thermocouple 18 or the like into the alloying chamber 4 and measuring the temperature of the hot air passing through the alloying chamber 4, it is possible to determine whether the temperature of the cylindrical body 10 and the wall surface of the alloying chamber 4 is heated to the required temperature. It is preferable that this is confirmed.

Next, the upper mold 2 and the lower mold 3 are held in a clamped state as shown in FIG. 500 in room 4
cc, molten S7 of pure aluminum (M degree 99.7%) at 800°C was introduced, and the molten metal 7 was heated to 1000°C by the plunger 9.
Pressure was applied at a pressure of k (1/c1 to '), and the pressurized state was maintained until the molten metal 7 was completely solidified. After the molten metal 7 was completely solidified, the upper mold 2 was released from the lower mold 3. The solidified body is taken out from the lower mold 3 using a knockout bin 12, 15, 16, and the solidified part in the pressurizing chamber 5 is removed by cutting with a saw, etc., and the solidified body is solidified in the alloying chamber 4. I took out the body.

Fig. 3 is a stereoscopic photograph showing a part of the cross section of the coagulated material taken out as described above, and in this Fig. 3, a is M.
b indicates a portion of n-Al alloy, b indicates a portion of A1-rich Mn-A1 alloy formed by diffusion of manganese into molten aluminum, and C indicates a portion containing only aluminum. Moreover, FIG. 4 is an optical micrograph showing the cross section of the central part of the MO-A1 alloy (portion a in FIG. 3) manufactured as described above at 100 times magnification.

Further, FIGS. 5 and 6 respectively show a solidified body and an Mn-A solidified body as a comparative example manufactured according to a conventional alloy manufacturing method.
1 is a stereoscopic photograph and an optical microscope photograph showing a cross section of the l alloy at 3x and 100x magnification. In this comparative example, the cylinder body 1
0 was preheated to 600°C outside the alloy manufacturing apparatus 9- and then placed in the alloying chamber 4 defined by the upper mold 2 and lower mold 3 which were heated to 250°C. The alloy was manufactured in the same manner and under the same conditions as in Example 1.

As can be seen from the comparison of FIGS. 3 and 4 with FIGS. 5 and 6, the Mn-Al alloy produced by the conventional method has many cracks (white line areas in FIG. 5). )-t5
Macro segregation (portions indicated by d and e in Figure 6)
In contrast, cracks and macro-segregation did not occur in the Mn-Al alloy produced by the method of the present invention, and the method of the present invention produced an alloy with a uniform structure. I understand what can be done. The macroscopic composition of the Mn-Al alloy produced in the above example was Mn-26,6%A.
It was 1.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to such embodiments, and it is understood that various embodiments are possible within the scope of the present invention. It will be clear to those skilled in the art.

[Brief explanation of the drawing]

1 and 2 are longitudinal cross-sectional views showing one alloy manufacturing apparatus suitable for use in carrying out the method for manufacturing an alloy of the present invention in a porous body heating process and an alloying process, respectively;
4 and 4 are stereoscopic photographs showing cross sections of a solidified body containing an Mn-Al alloy and an Mll-A1 alloy formed in one embodiment of the method for producing an alloy according to the present invention at 2x and 100x magnifications. FIGS. 5 and 6 are stereoscopic photographs showing cross-sections of solidified bodies containing Mn-Al alloys and Mn-Al alloys manufactured by conventional alloy manufacturing methods at 3x and 100x magnifications; This is an optical microscope photograph. 1... Alloy manufacturing equipment, 2... Upper mold, 3... Lower mold,
/l... Alloying chamber, 5... Pressurizing chamber, 6... Runway,
7... molten aluminum melting the second metal), 8.
... Cylinder bore, 9... Plunger, 10... Porous body (cylindrical body). 11...Cylinder bore, 12...Knockout bin. 13.14...Bore, 15.16...Knockout bottle, 17...Nozzle, 18...Heat lightning confrontation Applicant: Toyota Motor Corporation Representative Patent attorney
Masaki AkashiFigure 3 (x2) Figure 4Figure 5Figure 6

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 receiving a porous body comprising the first metal and a molten metal of the second metal. Using an alloy manufacturing apparatus having a mold cavity, the porous body is placed in the mold cavity, the porous body is heated by introducing hot air into the mold cavity, and the molten metal is introduced into the mold cavity. A method for producing an alloy, which comprises introducing a molten metal and permeating the molten metal into the porous body to alloy the first metal and the second metal.