JPH0483833A - Particle dispersed composite and its manufacture - Google Patents

Abstract

PURPOSE:To form parts with different compounding rates in a composite by pouring the molten metal of a matrix alloy in which ceramic particles are uniformly dispersed into the preform of ceramic particles. CONSTITUTION:Ceramic particles 1 are housed in a die 2 heated to about 100 to 400 deg.C and is pressurized by using an upper punch 3 and a lower punch 5 to form the preform 4 of the ceramic particles. A composite 6 in which ceramic particles are uniformly dispersed is heated and melted at about 650 to 850 deg.C, and this molten metal 6 is poured to the upper part of the preform 4. Next, pressurizing is executed by an upper punch 7 to infiltrate the molten metal 6 into the preform 4. By this pressurizing, the molten metal contg. the ceramic particles is infiltrated into the preform 4, by which a composite in which each part of A, B and C respectively has a different compounding rate can be obtd. The particle dispersed composite in which the compounding rates are always regulated to C>B>A can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a particle-dispersed composite material having partially different composite ratios and a method for producing the same.

b. Conventional technology Regarding composite materials, the following conventional techniques are known.

For example, after making a preform using fibers such as SiC or C or whiskers and setting it in a mold,
This is a method of making a composite material (FRM) by pouring molten metal such as an alloy and impregnating it into a preform under pressure.

There is also a composite casting method in which particles such as 5iCJpC are added to a completely or partially melted molten metal and mechanically stirred to form a composite material (MMC).

Furthermore, particles such as SiC and C and AI! A widely used method (powder metallurgy method) is to mix powders such as alloys and produce composite materials by hydrostatic compression, hot extrusion, sintering, or the like.

In addition, by mixing particles such as SiC or C with powder of Af gold alloy and applying hot mechanical agitation, S
There is a method (mechanical alloying method) in which particles such as iC and C are kneaded into a particle-dispersed composite material.

C1 Problems to be Solved by the Invention Fibers and whiskers such as SiC and C are expensive, and manufacturing a preform using them is labor-intensive, resulting in high product costs.

In addition, in the above-mentioned composite casting method, even if particles with good wettability are added to the molten metal, the addition ratio to the molten metal must be 20w in order to evenly and uniformly disperse the particles.
The upper limit is t%, and it is difficult to add more than this.

Furthermore, the alloy powder used in powder metallurgy is difficult to manufacture and therefore expensive, and has the disadvantage that it takes many steps to complete it as a composite material.

Since it is manufactured by extrusion, there is a problem in that it is limited to simple shapes.

In addition, the alloy powder used in the mechanical alloying method is expensive as mentioned above, the mixing ratio is limited to about 50 wt%, and an extrusion process is required to manufacture the product, which has the same problems as the powder metallurgy. be.

On the other hand, there have been few proposals regarding the production of composite materials with different composite ratios.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a particle-dispersed composite material having different composite ratios, which solves the above problems, and a method for producing the same.

Means for Solving Problems d and ill In accordance with the above object, the present invention uses Al or Mg alloy as a matrix, and provides a composite portion with a high ratio, a composite portion with a lower ratio, and a composite portion with an even lower ratio. The above problem was solved by creating a particle-dispersed composite material having the following.

Furthermore, the present invention solves the above problem by pouring a molten metal of a matrix alloy in which ceramic particles are uniformly dispersed into a preformed body of ceramic particles and pressurizing it to form parts with different composite ratios. did.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

In the present invention, ceramic particles are used as the additive material for the composite. As ceramic particles, for example, S
iC, Al toy, 5jJa+ TiC, WC+
Zr0z, BN, C or a mixture of these particles is used.

The particle size (average particle size) of this ceramic is 0.01~
A material in the range of 30 μ- is used. Particle size is 0.01 μ-
Anything less than this is difficult and expensive to manufacture, and it is difficult to form a uniform composite. Furthermore, if the particle size exceeds 30tIII, no improvement in the strength of the composite material to be produced can be expected.

As the matrix alloy, an alloy of 82 or M is used. For example, JIS AC4C, JIS MC7, etc.

First, ceramic particles (for example, SiC99wt%+
BN1wt% is used. This is a composite material with excellent wear resistance due to the high hardness of SiC and BN with lubricating properties. Preheat to temperature. If the preheating temperature is less than 300°C, the molten metal in contact will solidify immediately and will not penetrate between the ceramic particles sufficiently.If the preheating temperature exceeds 900°C, the molten metal in contact will solidify quickly. It is undesirable because it takes time and reacts with some components to form compounds.

Next, as shown in Figure 1(a), the temperature is 100 to 400°.
After placing the ceramic particles 1 in the mold 2 heated to C, as shown in FIG. Pressure is applied to form a preformed body 4 of ceramic particles. If the pressure P is 1 kgf/cj without a groove, the strength of the preformed body will not be increased, and there is a risk that it will be deformed or broken in a later process. On the other hand, the pressure P is loo00kg
If f/cd is exceeded, the particle density becomes too high, the molten metal added in a later step becomes difficult to penetrate, and problems arise in terms of the strength of the mold itself.

On the other hand, an alloy to be used as a matrix is separately prepared. This matrix alloy is A! A gold alloy or a QG alloy,
A composite material made of uniformly dispersed ceramic particles is used.

Examples of the alloy used include JIS AC8A, and examples of the Mg alloy include JIS AC8A. There is IC8.

Furthermore, the ceramic particles dispersed in the composite material are made of the same material as that used to form the molded body, such as Si.
C99wt%+BN1 wt% particles, or others such as SiC, Al 203. si3+14.
TiC, W.C.

ZrO□, BN, C1 or a mixture of these particles is used. Furthermore, the particle diameter of these ceramics is also within approximately the same range as that used for the molded body.

A composite material 6 made by uniformly dispersing such ceramic particles is heated and melted at a temperature of 650 to 850°C, and the molten metal 6 is poured onto the top of the molded body 4 as shown in FIG. 1(C). Supply hot water.

The melting temperature is set within an appropriate temperature range so as not to cause solidification to occur too quickly or to a high temperature that may cause inhalation of gas, etc.

For example, in the case of the above-mentioned materials, if the temperature is less than 650°C, solidification will be too rapid, and if the temperature exceeds 850°C, the temperature will be 11. ,N.

This is undesirable as it causes a lot of inhalation of gases such as.

Next, as shown in the same figure (d), 10
The molten metal 6 is permeated into the preform 4 by applying pressure P2 of 0 to 100100 O0/c4. In this case, when the pressure P2 is 100 kgf/ci and there is no groove, the penetration of the molten metal into the preformed body is insufficient, and 100100O0/C4
There is virtually no need to pressurize in excess of this amount.

By applying the pressure, the molten metal containing ceramic particles permeates into the molded body 4, and the resulting composite material is A.

Each part of B and C can be changed to a different compounding rate. That is, part A is the molten metal 6 containing ceramic particles.
The composition remains the same, part 0 is the one with the highest composite rate (50-90-t%), and part B is the part where the matrix alloy has moved into part C, resulting in an increase in ceramic particles. The compounding rate is the second highest after 0 parts (10~
70-t%). That is, the composite ratio is always changed to a particle-dispersed composite material in which C>B>A.

Fig. 2 shows an example of application to a valve lifter for a four-stroke engine. Ceramic particles 101 consisting of 99 wt% SiC + 1 wt% BN are preheated to 800°C, and the particles are heated as shown in Fig. 2 (a) and (b). The molded product 104 is then put into a mold 102 heated to 300° C. and pressed between an upper punch 103 and a lower punch 105 at a pressure PI of 100,100 O/cj to form a molded product 104.

Next, using JIS AC4C as the matrix alloy, SiC
Molten metal 10 made by heating and melting this at 750°C using a composite material made by dispersing 99 wt% + BN l wt%
6 into the molded body 1 in the mold 102 as shown in the same figure (C).
04 and pressurized with the upper punch 107 at a pressure P2 of 1000 kgf/c4 as shown in FIG.

After cooling, the product obtained by demolding has the best properties in terms of wear resistance and lubricity, with part 0, which corresponds to the cam sliding part at the top, having the best properties in terms of wear resistance and lubricity. The properties of a particle-dispersed composite material were obtained.

Figure 3 is a photograph showing the metallographic structure of the composite material according to the present invention.
Figure (a) shows a preformed body pressure-formed at 000/cd, which was then pressurized with a molten metal made of a 10-t% composite of 8C4C and SiC particles with an average particle size of 13μ. A,
Figure (b) shows the entire metal structure including parts B and C.
The figure (C) shows an enlarged view of the B part, the 0 part and the boundary between them, and the figure (B) shows an enlarged view of the 0 part. These photos clearly show the composite condition of each part.

e. Effects of the Invention As described above, according to the present invention, a particle-dispersed composite material in which the composite ratio of ceramic particles is different within the same material can be manufactured using a relatively simple casting method, and can be made by any method. The material and product shape can be changed.

Then, a composite material with a high composite ratio, which has excellent hardness, heat resistance, abrasion resistance, rigidity, and fatigue strength as a whole, and which has parts that are superior in these properties in parts and in stages, can be used.

[Brief explanation of the drawing]

Figures 1 (a), (C), and (d) are diagrams explaining the manufacturing procedure of the particle-dispersed composite material according to the present invention, and Figure 2 similarly explains the manufacturing procedure according to another example. figure, 3rd
Figures (a), (b), (C), and ■ are photographs of the metal structure of the composite material according to the present invention. Figure (a) shows the whole, Figure (b) shows part A, and (C) is part B and part 0,
The same figure (d) shows the enlarged version of the 0 part. 1.101... Ceramic particles, 2.102...
・Mold, 4.104... Preformed body, 6.106
...Molten metal. No. 3 (a) ×5 (C) (b) (d) X 4LJ (J

Claims (1)

[Scope of Claims] 1) A particle-dispersed composite material that uses Al or Mg alloy as a matrix and has a composite portion with a high percentage, a composite portion with a lower percentage, and a composite portion with an even lower percentage. 2) A particle dispersion type characterized in that a molten metal of a matrix alloy made of ceramic particles uniformly dispersed is poured into a preformed body of ceramic particles and pressurized to form parts with different composite ratios. Method of manufacturing composite materials.