Study on Forming and Properties of Heat Resistant Low Expansion High Silicon Aluminum Alloy Based on Genetic Algorithm

High-silicon aluminum alloy containing more than 16% Si has many advantages, such as light weight, wear resistance, heat resistance, small thermal expansion and so on, and has a wide application prospect in aerospace, automobile and machinery industries. In this paper, the influence of die casting based on genetic algorithm on the microstructure, mechanical properties and thermophysical properties of the developed high thermal conductivity and low expansion high silicon aluminum alloy is studied. The results show that, compared with the traditional gravity casting, the eutectic silicon phase of die casting is rmer, the alloy structure is better and more uniform, the as-cast tensile strength is increased to 192.4MPa, the average thermal expansion coefficient is $17.05\times 10^{-6\circ}\mathrm{C}^{-1}$, decreasing by about 3.54%, and the average thermal conductivity is increased to 146 W/(mk).