Research on Microstructure and Properties of TiB2/Al-Si Multi-Element Piston Alloy Composite

Abstract

The Al-12Si-4Cu-2Ni-0.9Mg was used as the matrix, TiB2/Al-12Si-4Cu-2Ni-0.9Mg composite material was prepared by adding Al-TiB2 in master alloy, and the mass fraction of TiB2 particles in the composite material was 3%. TiB2 particles were prepared by melt self-propagating direct synthesis method. Based on studying the influence of mechanical stirring speed on the distribution of TiB2 particles during the preparation of Al-TiB2 master alloy, the optimal mechanical stirring speed was optimized to 800 r/min. TiB2/Al-12Si-4Cu-2Ni-0.9Mg composite material was prepared by remelting and dilution method. The as-cast solidified structure of the composite material was mainly composed of α-Al matrix, Si phase and TiB2 particles, and TiB2 particles were evenly distributed. Under the condition of 360 °C(Working temperature of common piston), the tensile strength of the composite material was 15.4% higher than that of the base material, and the yield strength of the composite material was 29.4% higher than that of the base material.