Abstract:The characteristics of microstructures and mechanical properties of the multi-layer spray deposited SiC_P/Al-6.5Fe-0.6V-1.3Si, SiC_P/Al-8.5Fe-1.3V-1.7Si and SiC_P/Al-10Fe-1.3V-2Si composite sheets obtained by rolling after extruding were investigated. The evolution of the grain and phases of these composites during processing were examined, and the influence of the microstructures on the mechanical properties was analyzed. The experimental results show that the ultimate tensile strengths σ_b of the three kinds of composite sheets are 420, 535, 470 MPa respectively at room temperature, and 232, 285, 300 MPa at 315 ℃ and 148, 180, 200 MPa at 400 ℃. The excellent mechanical properties can be attributed to the high solid solubility, fine grain size, Al₁₂(Fe,V)₃Si precipitation particles and the SiC particles. And the composition of the matrix alloy has an obvious effect on the mechanical properties of the as-rolled sheets.

Key words: heat resistant alloy; composite; spray deposition; microstructure; mechanical property