Low-Si SiCp/Al composite material and preparation method thereof

Abstract

The invention discloses a low-Si SiCp / Al composite material and a preparation method thereof. The SiCp / Al composite material consists of the following raw materials in percentage by mass: 30 to 50 percent of infiltrated aluminum alloy, and the balance of SiC powder. The preparation method of the composite material comprises the following steps of: mixing the SiC powder of different grain diameters uniformly, filling the mixed SiC powder into a ceramic die, performing vibrating compaction or die pressing to obtain a SiC prefabricated part, placing the infiltrated aluminum alloy at the top of the SiC prefabricated part, putting the dried infiltrated aluminum alloy into a tubular furnace, performing pressure-free infiltration, performing heat preservation for 1 to 3 hours at the temperature of between 735 and 800 DEG C under the protection of nitrogen, and naturally cooling to room temperature to obtain the SiCp / Al composite material. The SiCp / Al composite material has the characteristics of high strength, thermal conductivity and the like, and the thermal expansion coefficient of the composite material can be reduced; and by the preparation method, reaction of molten aluminum and silicon carbide can be effectively prevented, and easily hydrolyzed products are not generated.

Description

1. Technical field [0001] The invention relates to a composite material and a preparation method thereof, in particular to a SiCp / Al composite material with low Si content and a preparation method thereof. 2. Background technology [0002] Metal matrix composites (Metal Matrix Composites, MMCs for short) are composite materials with wires, filaments, fibers, whiskers or particles as reinforcements and metals or alloys as the matrix, in which the reinforcement phase can be continuous phase or discontinuous phase . Generally, the metal matrix has good ductility but poor strength, while the reinforcement has high strength and stiffness. After the two are combined together, its stiffness, strength, and wear resistance are superior to traditional metal materials, with low thermal expansion coefficient and high heat resistance. , high specific strength, high specific modulus, wear resistance and anti-aging and other advantages, so that it has broad application prospects in aerosp...

AI Technical Summary

Problems solved by technology

At present, when preparing SiCp / Al composite materials with excellent comprehensive performance and good stability (no brittle interface products that are easy to hydrolyze), the silicon content of the aluminum matrix is ​​generally increased, and the infiltration is carried out at a high temperature, but this will affect The mechanical strength of composite materials; and at low silicon content, the phenomenon of brittle interface products that are easily hydrolyzed is easily produced by high temperature infiltration

[0007] At present, there is no report on the method of preparing SiCp / Al composite materials with low Si content by pressureless impregnation at relatively low temperature (735-800°C).

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