The Research Of SiCp/Al Composite Material Preparation Process And Property

SiCp/Al composite materials not only have many excellent mechanical properties such as high specific strength, high specific elastic modulus and wear resistance, but also have excellent thermal properties like low thermal expansion and high thermal conductivity. Therefore, they are widely used in automotive, military weapons, aerospace and electronic package, etc. Pressureless infiltration routine and powder metallurgy process has become a highly economic competitiveness of preparation technology in the area of prepare composite material.This dissertation prepared SiCp/Al composite materials with powder metallurgy method successfully. In order to get better preparation process, we studied the influence of the process parameters to the pressureless infiltration routine and the property of the composite. The process parameters involved the surface treatment of SiC, composition of aluminum alloys, aluminizing temperature and heat preservation time in this paper. In addition, the experiment, by making use of ceramic lined with a clever way, solved the problems like the stripping difficulty, container damage on the experimental conditions of pressureless infiltration routine for SiCp/Al composite material, and also the operation problem. The best method for no pressure alumetizing SiCp/Al composite material technology is what:the best parameters matching alloy is 10Mg-10Si-Al, the best alumetizing atmosphere is nitrogen atmosphere, the best alumetizing temperature is 1100℃, the best holding time is 2 h. During the program of the pressureless alumetizing technology was studied in 55% of the enhanced SiCp/Al composite specimens, HRA78 hardness and the bending strength for 276.1 MPa is the highest.This dissertation prepared SiCp/Al composite materials with powder metallurgy method successfully and mainly studied the influences of the weight ratio of ball to powder and milling time to SiC grain size as well as mixing uniformity. On the meanwhile, we also considered the influence of different cold pressing molding pressures of composite to density, compressive strength and hardness, the influence of different sintering atmospheres, temperatures and time of heat preservation to interface organization and bending strength of the composite material, the influence of the secondary processing technology by high temperature hot pressing to the materials, repair, density, hardness and bending strength. The experiment method for powder metallurgy SiCp/Al composite material technology is what: high-energy ball mill mix powder technology, the ball material than evenly distuibuted more sexual function, milling time take second place; the 200 MPa pressure cold forming,800℃vacuum sintering atmosphere and heat preservation 2 h, sample in 500℃and 350 MPa in heated hot under 10 min, can create the SiCp/Al composite specimens which H B284hardness and the bending strength for 182.4MPa is the highest.