Method for preparing aluminum silicon carbide composite material

Abstract

The invention discloses a method for preparing an aluminum silicon carbide composite material. Liquid metal aluminum is filled in a porous silicon carbide substrate which is prepared from spherical silicon carbide powder and spherical silicon powder which serve as raw materials and has a three-dimensional through hole structure through an injection molding process so as to form a bicontinuous phase, the density of the aluminum silicon carbide composite material and the product uniformity are improved, and a high-strength AlSiC substrate is obtained by changing molding pressure, adjusting ingredients of the spherical powder with different particle sizes, adding a pore-forming agent, and sintering at the temperature of between 1,400 and 2,400 DEG C. The porous substrate is fixed in a cavityof an injection machine, and the liquid metal aluminum enters the cavity from an injection port and is filled in through holes of the AlSiC substrate through a gas-liquid mixed injection process so as to form the aluminum silicon carbide composite material with a silicon carbide and metal aluminum bicontinuous phase structure. The aluminum silicon carbide composite material prepared by the process has the heat conductivity of 190 to 280 W / mK and the thermal expansion coefficient of 5.5 to 11.5*10(-6)K at room temperature of 200 DEG C, and has high rigidity, low density, high weldability and low machining amount.

Description

technical field [0001] The invention relates to a low-cost preparation process of aluminum silicon carbide high-strength composite material, and is particularly suitable for the preparation method of aluminum silicon carbide composite material with adjustable aluminum content, good laser weldability, high thermal conductivity and low thermal expansion coefficient. Background technique [0002] Porous silicon carbide ceramics and metal materials such as metal aluminum, copper, silicon, etc., can be obtained by compounding the metal-based ceramics, which are electronic packaging materials with thermal expansion coefficient matching that of silicon chips, good thermal conductivity and high air tightness, which solves the problem of traditional electronic packaging materials. The thermal expansion coefficient of the silicon chip does not match the expansion coefficient of the silicon chip and the density is too high, which provides the basis for the packaging of high-power electr...

AI Technical Summary

Problems solved by technology

[0002] The metal-based ceramics that can be obtained after the composite of porous silicon carbide ceramics and metal materials such as metal aluminum, copper, silicon, etc. have a thermal expansion coefficient that matches the silicon chip, good thermal conductivity, and high air-tightness. It solves the problem of traditional electronic packaging materials. The thermal expansion coefficient does not match the expansion coefficient of the silicon chip and the density is too high, which provides the basis for the packaging of high-power electronic components

The patent [CN 101092672A] discloses a method for preparing cermets, but currently all silicon carbide-based metal composite materials are difficult to machine and surface treat, so the production cost of the product is high; silicon carbide powder is used in the preparation process of the porous body The shape of the body is uncontrollable, resulting in closed pores and inner pores in the shape of ink bottles, large head loss caused by capillary pressure during aluminizing treatment, poor product uniformity and air tightness

Images