TiB₂颗粒增强 A356 复合材料的组织及力学性能研究

Al-10TiB₂ intermediate alloy was prepared by ultrasonic assisted molten salt reaction method,and 5%TiB₂/ A356 composite with homogeneous microstructure and high strength was fabricated via ultrasound assisted remelting and dilution approach. The microstructure and mechanical properties of the composites were investigated. The results indicate that the microstructure is homogeneous without residual impurity salt. The size of α-Al grains is decreased from 250 μm to 190 μm,which is reduced by 24%,after adding 5% TiB₂ particles. Moreover,the yield strength and tensile strength of as-cast composites are 124 MPa and 175 MPa,which is enhanced by 12.7% and 6.1%,respec-tively,in comparison with those of A356 alloy. The yield strength and tensile strength of heat-treated composites are 250 MPa and 290 MPa,which is enhanced by 19.0% and 13.7%,respectively,in comparison with those of A356 alloy.