JPS6270538A - Manufacture of ceramics grain-dispersed composite alloy - Google Patents

Abstract

PURPOSE:To obtain the titled composite alloy in which individually independent ceramics grains are dispersed, by adding a mixture in which ceramics grains and metallic grains are uniformly dispersed to a molten metal and by mixing them by agitation. CONSTITUTION:The ceramics grains and the metallic grains for dispersion consisting of Al or alloys thereof, etc., each having average grain size ranging from 10 to 100mum, are mixed by agitation by means of a mixer and, by the use of coagulated or easily coagulating ceramics grains and metallic grains for dispersion, the mixture of both grains uniformly and independently dispersed is formed. Then this mixture is added to the molten metal, which is mixed by mechanical agitation, so that ceramics grain-dispersed composite alloy in which independent ceramics grains are uniformly dispersed in the metal can be obtained. As the above molten metal, Al or its alloys are used and, as the ceramics grains, grains of oxides such as alumina, zirconia, etc., silicon nitride, etc., are used, respectively. The above-mentioned composite alloy is useful as a new material improving strength at high temp., wear resistance and lubricity.

Description

Detailed Description of the Invention <Industrial Application Field> The present invention allows fine ceramic particles (001 to 1000 μm), which are normally extremely likely to agglomerate, to be easily mixed with metal particles such as aluminum through pretreatment. The present invention relates to a method for uniformly dispersing individual ceramic particles in molten metal by mechanical stirring and mixing.

This ceramic particle-dispersed composite alloy is expected to emerge as a metal composite material with properties that improve high-temperature strength, wear resistance, and lubricity.

<Prior art and its problems> Conventionally, in the case of aluminum-based composite alloys, for example, the method for manufacturing ceramic particle-dispersed composite alloys involves forming an oxide film of approximately several tens of I11 on the surface of aluminum particles in an oxidizing atmosphere; A surface oxidation method in which ceramic particles are manufactured by hot extrusion after powder compacting, and a spray dispersion method in which ceramic particles are injected into a flowing molten metal to introduce the ceramic particles into the molten aluminum. The above surface oxidation method has a complicated manufacturing process, alumina (oxide film) does not exist within the aluminum grains, the amount of alumina cannot be increased, and there is a limit to the distribution of alumina particles, so it is difficult to strengthen aluminum. There are also limits. In addition, in the above injection dispersion method, the ceramic particles are injected together with an inert gas into the molten metal that is moving, so the yield of the ceramic particles is extremely poor, and the amount of ceramic particles added cannot be increased.
Furthermore, the environment becomes worse because the particles are scattered around. In other words, these conventional methods suffer from the complexity of the manufacturing process, the yield rate, and
There are technical problems with increasing the size, and these problems need to be resolved for practical use.

<Purpose of the Invention> This invention was made to solve the conventional problem as mentioned above, and provides a method for industrially manufacturing a composite alloy having the characteristics required for a ceramic particle dispersed composite alloy. This is what we provide.

<Means for Solving the Problems> The present invention provides a method for producing a ceramic particle-dispersed composite alloy having a large number of ceramic particles by adding ceramic particles to molten metal and stirring the mixture. The metal particles for dispersion such as alloys are mixed in a mixer, and the ceramic particles that are agglomerated or easily agglomerated are mixed with the metal particles for dispersion to create a mixture of ceramic particles and metal particles that are uniformly and independently dispersed, and this is melted. This method produces a ceramic particle-dispersed composite alloy in which individual ceramic particles are uniformly dispersed in the metal by mechanically stirring and mixing the metal. As the molten metal, aluminum or its alloy is preferably used, and as the metal particles for dispersion, aluminum or its alloy is preferably used, but other metals are also applicable. In addition, as ceramic particles (oxides such as alumina and siliconia, nitrides such as silicon nitride and sialon, carbides such as silicon carbide and graphite, and borides such as decnium boride), ceramics are added to the aluminum particles. After 1 to 80% by weight of particles are added and mixed, 5 to 50% by weight of the mixture may be added to the molten aluminum and dispersed by stirring.

<Examples and effects> Example 1 65 g of alumina particles with an average particle size of 80 μm and an average particle size of 10
85 g of 0 μm aluminum particles were previously combined in a ball mill. 500g of purity 9 kept in a molten state at 740°C in a #1o aluminium crucible in an electric furnace
Mix 10g of calcium with 99% pure aluminum (Japanese Patent Application Laid-open No. 5 (I-141960) j, 5 for thickening)
After mechanically stirring for 1 minute (with a rotary blade), the entire amount of the above mixture was added to the molten aluminum while stirring,
After stirring in a furnace for about 5 minutes, the mixture was cooled and solidified to obtain a ceramic particle-dispersed composite alloy. This composite alloy (yo, microscopic vl
According to the fl1111 inspection, it was found that the alumina particles added to the aluminum were not aggregated but were individually dispersed.

That is, in this case, by adding a premixed mixture of aluminum particles and alumina particles to molten aluminum, it became possible to easily produce a composite alloy in which independent alumina particles were uniformly dispersed in aluminum.

Comparative Example 1 After adding and mixing 10 g of calcium to 500 g of pure aluminum kept at 740°C by the method of Example 1 and performing a thickening treatment, 25 g of alumina with an average particle size of 15 μm was gradually added. Stir in the oven for about 5 minutes, cool, and solidify.
A ceramic particle dispersed composite alloy was obtained. This composite alloy has alumina uniformly dispersed in aluminum, but
Dozens of alumina particles are aggregated and dispersed in aluminum, making it impossible to produce a ceramic particle-dispersed composite alloy in which each alumina particle is independent.

Example 2 A mixture was prepared by uniformly mixing 65 g of alumina with an average particle size of 4 μm, 45 g of aluminum with an average particle size of 50 μm, and 40 g of aluminum with an average particle size of 50,071 m using a ball mill. Calcium was added to 500 g of molten pure aluminum at 740° C. to thicken the molten metal using the method of Example 1, the mixture was added, stirred for 5 minutes, and then cooled and solidified to produce a ceramic particle-dispersed composite alloy. In this case, as in Example 1, the alumina particles are individually and uniformly dispersed in aluminum to form a composite alloy.

In the case of such fine alumina particles and aluminum particles, by adding second aluminum particles larger than these particles, it became possible to easily mix and disperse ceramic particles with small particle sizes.

Comparative Example 2 A mixture of 65 g of alumina with an average particle size of 4 μm and 85 g of aluminum with an average particle size of 100 μm was prepared by the method of Example 1. 1 for 500g of pure aluminum molten metal at 740℃
After adding 0 g of calcium to thicken the mixture, the mixture was stirred for 5 minutes, cooled and solidified to produce a ceramic particle dispersed composite alloy. In this case, as in Comparative Example 1, a composite alloy was obtained in which dozens of alumina particles were aggregated and dispersed in aluminum, making it impossible to manufacture the desired composite alloy in which individual alumina particles were dispersed.

Example 3 30 g of silicon carbide with an average particle size of 04 μm by the method of Example 2
A mixture was prepared by uniformly mixing and dispersing 60 g of aluminum particles having an average particle size of 50 μm and 130 g of aluminum particles having an average particle size of 500 μm. After thickening 500 g of pure aluminum molten metal at 740° C., the mixture was added and stirred for 5 minutes, and then cooled and agglomerated to produce a ceramic particle molecule 11 composite alloy. This composite alloy has ultra-fine 04μm
The silicon carbide particles are individually and uniformly dispersed in aluminum to form a composite alloy.

In this way, as in Example 2, by adding second aluminum particles with a larger particle size to the ultra-fine ceramic particles to create a mixture in which the ceramic particles are uniformly dispersed, it is possible to easily disperse the ceramic particles. It has become possible to manufacture a ceramic particle-dispersed composite alloy in which ultra-fine ceramic particles are dispersed in aluminum.

Example 4 According to the method of Example 1, a mixture was prepared by uniformly mixing alumina particles with an average particle size of 4 μm and 350 g of copper particles with an average particle size of 100 μm. After melting 2000 g of pure copper at 1200° C., 40 g of calcium was added to thicken it, the above mixture was added in its entirety, stirred for 5 minutes, and then cooled and solidified to produce a ceramic particle dispersed composite alloy. This composite alloy has fine alumina particles uniformly dispersed in copper.

This principle can also be applied to other metals.

<Effects of the Invention> As explained above, the detailed description of the present invention is as follows.
After that, the mixture is stirred and mixed into the molten metal, making it easy to mix and making it possible to manufacture a ceramic particle-dispersed composite alloy in which individual ceramic particles are dispersed, making it possible to manufacture on an industrial scale. It is possible. This metal composite material is useful as a new material that improves high-temperature strength, wear resistance, and lubricity.

[Brief explanation of drawings]

FIG. 1 is a photograph of the metallographic structure of the polished surface of the ceramic particle dispersed composite alloy of Example 2 manufactured according to the present invention. Ceramic particles of 4 μm are observed to be individually dispersed. FIG. 2 is a photograph of the metallographic structure of the polished surface of the ceramic particle-dispersed composite alloy of Comparative Example 2. It is observed that ceramic particles of 4 μm are aggregated. Figure 1

Claims (1)

[Claims] 1. A method for producing a ceramic particle-dispersed composite alloy consisting of a large number of independent ceramic particles by adding ceramic particles to molten metal and stirring the mixture,
By pre-mixing ceramic particles and dispersing metal particles having one type of particle size range in a mixer to create a mixture of ceramic particles separated by metal particles, this is added to molten metal and mixed by stirring. , a method for manufacturing a ceramic particle-dispersed composite alloy in which ceramic particles are individually dispersed in a metal. 2 Aluminum or its alloy as the molten metal, oxides such as alumina and zirconia as the ceramic particles,
Nitrides such as silicon nitride and sialon, carbides such as silicon carbide and graphite, and borides such as titanium boride have an average particle size range of 10 to 1000 μm, and aluminum or its alloys have an average particle size of 10 to 1000 μm as metal particles for dispersion. After mixing, the weight ratio of the ceramic particles to the aluminum particles is arbitrarily changed from 1:99 to 80:20, and then 20 to 50% by weight of the mixture is added to the molten metal and stirred and mixed. 2. The method for producing a ceramic particle-dispersed composite alloy according to claim 1, wherein the ceramic particles are dispersed in an amount of 0.2 to 40% by weight. 3 In a method for manufacturing a ceramic particle dispersed composite alloy, agglomerated fine ceramic particles and two or more types of dispersing metal particles having different particle size ranges are mixed in a mixer to form a mixture of independent fine ceramic particles. A method of manufacturing a ceramic particle-dispersed composite alloy in which fine ceramic particles are dispersed by adding it to molten metal and stirring it. 4 Average particle size as ceramic particles: 0.01 to 20μ
m range, first aluminum particles having an average particle size of 1 to 2000 times that of the ceramic particles, and second aluminum particles having an average particle size of 1 to 200 times that of the first aluminum particles. Ceramic particles, in which the weight ratio of the ceramic particles to the aluminum particle mixture is arbitrarily changed from 99:1 to 20:80, in which the mixing ratio of the particles and the second aluminum particles is arbitrarily changed from 1:99 to 90:10. Fine ceramic particle dispersion according to claim 3, characterized in that the fine ceramic particles are individually dispersed by adding 5 to 50% by weight of a mixture of aluminum particles and aluminum particles to the molten metal and stirring and mixing. Method for manufacturing composite alloys.