| The1350/SiCp and2024/SiCp composites are cast by conventional direct chilling (DC) casting and low frequency electromagnetic casting (LFEC), the SiCp is the strengthening phase for1350and2024aluminium alloys, and the SiCp is added into the aluminium alloy matrix by agglomerate which is sintered by pure aluminum powder and SiCp. In this work, the as-cast and as-homogenized microstructures of1350,2024aluminium alloys and composites are studied. The evolution of microstructure and performance of1350aluminium alloy and1350/SiCp composite is studied after the ingot is extruded. The evolution of microstructure and performance of2024aluminium alloy and2024/SiCp composite is studied after the ingot is extruded and solid solution and aging treatment are carried out.During the low frequency electromagnetic casting, the coacervate n-SiCp were distributed uniformity in the2024and1350aluminium alloy with Lorentz force.The residual phases distribute in the aluminum matrix after1350aluminium alloy,2024aluminium alloy and composites are extrude, and the grains were lengthened in longitudinal section.The tensile strength and of1350/SiCp and2024/SiCp composites is higher than that of1350aluminium alloy and2024aluminium alloy, which raised55.5percent and1.2respectively, and the elongation rate decreased40.1percent and14.6percent.After solution heat treatment(480℃,1h), the residual phases in the extruding bars of2024aluminium alloy and2024/SiCp composite dissolve into the matrix and form the supersaturated solid solution, and the grains of the extrude bar grow up as recrystallization. The hardness and strength of2024/SiCp composites is higher than that of the2024aluminium alloy, the elongation rate and conductivity is lower than that of2024aluminium alloy. During the process of aging treatment with2h,4h,6h,8h and16h, the hardness and tensile strength reached to a maximum value, the elongation rate decrease to a minimum value when the aging time is8h. |
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