Effect of heat treatment on microstructure and properties of Si_P/Al-Cu composites prepared by HIP

50%SiP/Al-Cu and 70%SiP/Al-Cu composites were prepared by hot isostatic pressing(HIP) method using pure elemental powders.The microstructure evolution and dissolution of Al2Cu were studied.The properties of as-hot isostatic pressed composites before and after heat treatment were also investigated.The results show that the prepared SiP/Al-Cu composites are fully dense.The silicon particles well distribute in Al matrix and still keep the original size.The presence of Al2Cu,Si and Al is identified in the as-hot isostatic pressed composites.The Al2Cu phase is formed in the boundaries of the Cu and Al particles.After solution treatment,Al2Cu phase dissolves into the 70%SiP/Al-Cu composites,however,some Al2Cu phase does not dissolve into the matrix of 50%SiP/Al-Cu composites completely.After the peak-aged treatment,the bending strength of 50%SiP/Al-Cu and 70%SiP/Al-Cu composites as-peak-aged is 548 MPa and 404 MPa,which is increased by 38.81% and 13.51% compared with that of as-hot isostatic pressed,the three points bending of the composites can be improved remarkably.