JPS648690B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for producing an aluminum-based composite material, which is a composite material of aluminum or aluminum alloy and particles having a higher melting point than that of aluminum or an aluminum alloy, and particularly relates to type of particles (inorganic particles and metal particles),
The present invention relates to a method of manufacturing an aluminum-based composite material by arbitrarily selecting the shape, composite location, etc. according to the intended use of the composite material.

(Prior art and problems) Dispersion composites of metal and ceramics, dispersion composites of synthetic resin and inorganic materials, etc. are well known, but composites of aluminum and particles with a higher melting point are known. A particle-dispersed aluminum-based composite is also known, and its production method involves filling a homogeneous mixture of inorganic particles and metal particles into a heat-resistant and pressure-resistant mold, and preheating this to a temperature below the melting temperature of aluminum. After that, molten aluminum is poured into the same mold, and a hydraulic press is used to press it into the gaps between particles in the filled particle mixture, where it is cooled and solidified.

In addition, in order to manufacture a composite in which inorganic particles and metal particles are partially dispersed, that is, in which particles are dispersed only in the surface layer of a cylindrical body as shown in Fig. 4, first, as shown in Fig. 3, A small-diameter aluminum cylindrical body is placed in the center of a pressurized mold, and the space between it and the pressurized mold is filled with particles by falling from above, and then molten metal is further poured into the mold from above. It can be manufactured by pouring molten metal and then pressurizing it with a press. However, it is very difficult to fill the voids in a mold with particles in a desired pattern and maintain that state while pouring and press-fitting molten metal. However, if it is subjected to slight vibration or shock,
It immediately collapses and it becomes impossible to obtain a complex with that pattern.

(Means for Solving the Problems) The present invention has been made in view of the above points, that is, a method for manufacturing a composite material consisting of aluminum or aluminum alloy and particles having a higher melting point than the aluminum or aluminum alloy. , a continuous porous molded body in which aluminum alloy grains are joined to each other in point contact with a small amount of binder, and aluminum or aluminum mixed with or in addition to the high melting point grains. The alloy particles and the continuous porous formed body, in which the particles are joined to each other in point contact with a small amount of adhesive, are placed in a pressure mold according to the shape and structure of the composite material to be manufactured. While maintaining the pressure mold and the molded body in the mold at a temperature slightly lower than the melting temperature of the aluminum or aluminum alloy, pour the molten aluminum or aluminum alloy into the pressure mold and heat it. Press,
The aluminum or aluminum alloy is press-fitted into the intergranular spaces of the molded body in the mold, cooled and solidified, and then removed from the mold. A method for producing a dispersed particle-dispersed aluminum-based composite material is provided.

(Detailed Description of Means) The method for manufacturing the particle-dispersed aluminum composite material of the present invention will be described in detail below.

Aluminum or aluminum alloy The technical idea of the present invention is that aluminum, copper, lead, zinc, etc. can be selected and used depending on the purpose of use. Aluminum or an aluminum alloy was selected from the viewpoint of ease of machining. Specifically, aluminum metal alone, aluminum and silicon, manganese,
Aluminum alloys containing about 80% by weight or more of aluminum, such as alloys with magnesium, copper, zinc, etc., or alloys with small amounts of iron, nickel, titanium, etc., are used.

Composite Particles It is important that the inorganic particles and/or metal particles composited with the aluminum or aluminum alloy have a higher melting point than the aluminum or aluminum alloy. Such particles usually include pitch coke, petroleum coke, charcoal, carbon particles such as graphite electrode scrap, metal oxides such as aluminum oxide, magnesium oxide, iron oxide, chromium oxide, zirconium oxide, silicon nitride, aluminum nitride, etc. nitride, silicon carbide,
Carbides such as boron carbide, salt, potassium chloride,
These include chlorides such as barium chloride, glass particles such as quartz glass and crystallized glass, and metal particles such as iron, copper, nickel, titanium, cobalt, chromium, and manganese. Among these particles, in the case of water-soluble chloride, by eluting the chloride with water after compounding, a porous and breathable material can be obtained, and in the case of glass particles, translucency can be imparted. can be done.

The shape of the inorganic particles and/or metal particles used in the present invention is arbitrary, and the particle size is about 1 μ to 5 mm.
It is possible to combine the above. 50μ
~5mm, the pressing force of the molten metal press-fitted into the gap between the particles is generally less than 500Kgf/ ^cm2 , but when the particle size is about 50μ or less, production is possible with a pressure of 500Kgf/cm2 or less.
It is necessary to pressurize at gf/cm ² or more. Generally, as the pressing force increases, the generation of cavities and pinholes can be prevented, and a composite with an extremely good composite state can be obtained.

Production of continuous porous molded body (preformed body) Before the inorganic particles or metal particles are placed in a pressurized mold, the type and particle size of the particles to be composited are selected in advance according to the purpose of use of the composite material, and the particles are mixed. The composite structure is determined in advance to determine where and how the particles will be dispersed in the product composite material, and the pressurized type can be used to perform partial dispersion in which particles are dispersed partially in a part of the material, layered dispersion in which they are dispersed in layers in the material, etc. In order to form a partial composite or a layered composite in an arbitrary location in an arbitrary state and at an arbitrary dispersion ratio, the particles are preliminarily shaped into such a shape by using a binder or by partially sintering the particles. A molded body having communicating pores is formed in advance. As the binder used in molding the molded article, well-known organic binders for ceramic molding having good thermal decomposition properties can be used, and among these, furan resin binders are one of the preferred ones. The amount of the binder used is preferably a small amount that allows the particles to be bonded in a point contact state, and is usually 1.0 to 2.0% of the amount of binder used for the particles.
% by weight, and the amount may be small enough that the particle molded body does not break in the pressurized mold. Most of the binder evaporates and disappears during the preheating stage, but some remains in the form of carbide. However, the residual amount is such that it has almost no effect on the composite of particles, and a composite with an extremely good dispersion state can be obtained without bonding between individual particles.

The small amount of the binder and the inorganic particles and/or metal particles are mixed, put into a preforming mold, molded into a predetermined shape, and then taken out from the mold.

The molded body taken out is cut into various shapes by cutting, cutting, etc., or a plurality of bodies are combined, and the molded body is placed at an appropriate location in the pressurizing mold.

Aluminum or an aluminum alloy is composited into the particle molded body thus obtained, and an example thereof will be explained below based on the drawings for better understanding.

FIG. 1 is a perspective view of different types of cylindrical and cylindrical porous molded bodies 1 and 2 formed using inorganic particles and/or metal particles, and FIG. 2 is a perspective view of molded bodies 1 and 2 of FIG. 1. Perspective view of assembled body, 3rd
The figure is a longitudinal sectional view of a pressurizing device for manufacturing a composite by disposing and mounting the combined molded bodies of Fig. 2 in a pressurizing mold, and Fig. 4 shows a longitudinal sectional state of the manufactured composite. .

First, as shown in Figure 1, for the part to be composited, the combination of aluminum or aluminum alloy particles and each composite particle is adjusted according to the composite position, dispersion form, dispersion ratio, etc., and an organic binder is added. A particle molded body 1 is manufactured by mixing the particles. In addition, for the parts that are not combined, a particle molded body 2 is manufactured using only aluminum or aluminum alloy particles.

Next, as shown in FIG. 2, the particle molded bodies 1 and 2 are combined.

Composite As shown in Figure 3, the mold 3 is fixed to the stand 4, and the mold 3
A mold release agent such as graphite or boron nitride is applied to the inner surface of the mold. The frame 4 is provided with a gas vent hole 5 for discharging binder decomposition gas and air, and a wire mesh 6 is placed above the gas vent hole 5 to prevent the particles of the molded body from falling through the gas vent hole 5 due to pressure. put. The combined particle molded body as shown in Fig. 3 is placed on the inner bottom of this mold 3, and the mold is heated to a temperature lower than the melting temperature of the inorganic particles and/or metal particles and slightly higher than the solidification temperature of the aluminum metal. Heat to maintain a low temperature. Next, the molten aluminum metal 7 is poured into the upper part of the metal, and while maintaining the molten state, the molten aluminum metal 7 is poured into the gaps between the particles using the cylinder 8 of a hydraulic press.
Press in with a pressure of about 400Kgf/cm ² . As a result, the air in the interparticle spaces is discharged to the outside through the continuous pores, etc., and the gas created by the combustion of the organic binder in the particle layer passes through the wire mesh 6 and the gas vent holes 5. The aluminum metal 7 in a molten state is filled.

As a result, the aluminum-based metal particles 2 in the combined particle molded body are integrated with the molten aluminum-based metal molten liquid 7, and an aluminum-based composite with particles dispersed on the surface is formed in the state shown in FIG. It becomes material 9. At this time, since the preheating temperature of the combined particle compacts 1 and 2 is set slightly lower than the solidification temperature of the aluminum-based metal particles 2,
The pressurized aluminum metal 7 in a molten state flows into the interparticle gap without solidifying, and flows into the gas vent hole 5.
When it reaches the vicinity, it is cooled by the outside temperature and solidifies. Therefore, the molten metal does not continue to flow out through the gas vent hole 5.

Furthermore, even after the flow of the molten metal is stopped, by keeping it under pressure until it cools down, some of the residual liquid phase is integrated with the aluminum-based metal particles 2 inside the mold.
It acts extremely effectively on adhesion, coagulation, and shrinkage between molten metal and dispersed particles.

Product Composite Material The partially dispersed or layered composite material produced in this way can be used as a product as it is.
Alternatively, it can be used as a member of a machine, a device, etc., or it can be further machined by cutting, threading, etc. the aluminum or aluminum alloy body part outside the particle dispersion part. In this way, the composite material can be used as wear-resistant, vibration-absorbing, corrosion-resistant, heat-resistant, members, etc.

(Example) Example 1 A furan resin binder was applied to aluminum metal particles with a particle size of 1 to 2 mm.
After blending 1.0 to 2.0% by weight and mixing uniformly, it was molded into a cylindrical molded body with an outer diameter of 20 mmφ and a height of 30 mm.

In addition, furan resin binder was added to graphite electrode scrap with an average particle size of 1 mm in an amount of 1.0 to 2.0% by weight based on the graphite electrode scrap particles, and after uniformly mixing, the inner diameter was 20 mm.
A hollow cylindrical molded body with a diameter of 30 mm and a height of 30 mm was molded.

Next, the cylindrical molded body was inserted into the hollow part of this hollow cylindrical molded body, and the two types of particle molded bodies were combined and dried at 110° C. for 1 hour.

On the other hand, a cylindrical pressure-resistant mold with an inner diameter of 30 mmφ, an outer diameter of 48 mmφ, and a height of 75 mm was manufactured, and the pedestal at the bottom of this mold was provided with four gas vent holes with a diameter of 3 mmφ, and the top surface was made of stainless steel with a diameter of 30 mmφ. A wire mesh was placed, and graphite mold release agent was applied to the inner surface of the mold.

Then, the combined particle compact is inserted into the mold from above, and the mold is preheated to a temperature of 600°C, which is below the melting temperature of the aluminum metal particle compact, and the compact in the mold is heated to about the same temperature. After that,
Molten aluminum at 780℃ is poured into the mold from above, and then the molten aluminum is pressurized from above the mold using a hydraulic press cylinder with an outer diameter of 30mmφ at a pressure of 400Kgf/cm ² to form compact particles. It was press-fitted into the gap and the contact gap between the molded bodies. After press-fitting, the composite was cooled and taken out.

The obtained aluminum-based composite material has aluminum metal molten metal that has sufficiently penetrated into the interparticle gaps of the compact particles, the aluminum metal particles are integrated with the molten aluminum metal, and graphite electrode scraps are dispersed in the surface layer. It was a system complex. This composite has the physical and chemical properties of an aluminum metal body inside, and the surface layer has properties such as wear resistance and vibration absorption, so it can be used as a sliding material, a bearing member for rotating parts, etc. , is an extremely useful material.

Example 2 Graphite electrode scraps with average particle size of 0.15 mm, average particle size of 0.4 mm
Three types of particles were selected: graphite electrode scrap with an average particle size of 1.0 mm, and furan resin-based binder was added to each of the three types of particles at a rate of 1.0 mm per particle.
~2.0% by weight was blended, and after mixing, each was molded into a disc-shaped molded product with a size of 30 mmφ x 5 mm, and each was dried at 110° C. for 1 hour.

A molded plate formed by forming these three disk-shaped molded bodies from graphite electrode scraps having an average particle size of 0.15 mm as an upper layer,
A molded plate formed from graphite electrode scraps with an average particle size of 0.4 mm was used as the middle layer, and a plate-shaped plate formed from graphite electrode scraps with an average particle size of 1.0 mm was stacked on the lower layer to form a three-layer structure. It was loaded into a similar pressure mold. These molded bodies were preheated to a temperature of 600℃, while molten aluminum alloy (JIS-AC4A:AL-Si-
A molten aluminum alloy (Mg-based aluminum alloy) is poured into the mold, and a hydraulic press cylinder with an outer diameter of 30 mm is used from above the mold to press the molten aluminum alloy at a pressure of 600 Kgf/cm ² to create spaces between the particles of the compact. It was press-fitted into. After press-fitting, the mixture was cooled and demolded to obtain a composite.

In the obtained aluminum-based composite, the molten aluminum metal sufficiently permeated throughout the interparticle gaps between the molded body particles, and a composite material in which each particle was laminated in three layers was obtained.

Similar to Example 1, this composite material has functions such as wear resistance and vibration absorption, and the material is also lightweight, so it can be used as a sliding material as in Example 1.

(Effects of the Invention) According to the present invention, as described in detail in the Examples and the like, a plurality of continuous porous molded bodies made of inorganic particles and/or metal particles that have been previously molded into a certain shape are combined to form a molded body in a pressure mold. By arranging them at appropriate positions, it is possible to accurately and easily produce a composite material in which particles are dispersed in a complicated pattern depending on the desired use of the composite material. Such a material is expected to have a significantly expanded field of use compared to a composite material with a simple structure, and the present invention is extremely advantageous in that it can provide an easy manufacturing method for such a novel composite material.

All you have to do is place the pre-formed blocks of a certain shape into the mold like building blocks, so you don't have to pay close attention to filling specific parts of the mold with granules like in the conventional method. It is extremely easy to work with and operate, and can significantly speed up production.

As described above, the present invention is a method for manufacturing a composite material that exhibits excellent effects and greatly contributes to this field.

[Brief explanation of drawings]

Figures 1 to 4 are drawings showing materials, devices, etc. for explaining one embodiment of the present invention, and Figure 1 is a perspective view of a molded body formed into a cylindrical shape and a columnar shape from inorganic particles or metal particles. , Figure 2 shows 1 and 2 in Figure 1.
FIG. 3 is a vertical sectional view of a pressurizing device for pouring molten aluminum into the pressurizing molds arranged in combination in FIG. 2 and press-fitting the molten aluminum; FIG. 4 represents a longitudinal cross-sectional view of the obtained composite. 1, 2: Open porous molded body, 3: Pressure-resistant mold,
4: Frame, 5: Gas vent hole, 6: Wire mesh, 7: Molten aluminum, 8: Hydraulic press cylinder,
9: Aluminum composite material.

Claims (1)

[Claims] 1. In a method for producing a composite material consisting of aluminum or aluminum alloy and particles having a higher melting point than those, the particles of aluminum or aluminum alloy are brought into point contact with each other using a small amount of a binder. A small amount of adhesive is used to make point contact between the continuous porous formed body and the high melting point particles or the aluminum or aluminum alloy particles mixed therewith. The communicating porous molded bodies, which are joined to each other in a state of While maintaining the temperature slightly lower than the melting temperature of aluminum or aluminum alloy, molten aluminum or aluminum alloy is poured into the pressurizing mold and pressurized, and aluminum or aluminum alloy is poured into the gaps between particles of the molded body within the mold. A method for producing a particle-dispersed aluminum-based composite material in which particles having a higher melting point than aluminum or an aluminum alloy are partially dispersed, the method comprising press-fitting, cooling and solidifying, and then demolding. 2. The method for producing a particle-dispersed aluminum composite material according to claim 1, wherein the binder of the particles is a furan resin adhesive.