Characteristics and Mechanical Properties of Al₇₅Si₂₅ Alloy Prepared by Rapid Solidification and Spark Plasma Sintering

Coarse primary silicon, a common flaw in aluminum alloy, seriously affects the processing and mechanical properties. In this paper, a ultra-fine grain Al₇₅Si₂₅ bulk materials were prepared by melt spinning rapid solidification combined with ball-milling and spark plasma sintering(SPS). It is found that, the rapid solidification microstructure and properties of alloy can be preferably reserved. The primary Si phase was uniformly dispersed in matrix with the sintering temperature of 320℃ and pressure of 500 MPa. The grain is very fine. Si element is supersaturated in the matrix, the density of alloy is above 98%. The micro-hardness and the yield strength are 298 Hv and 674 MPa, respectively. Therefore, the prepared alloy possesses excellent mechanical properties.