Effects of alloying elements on the phase constitution and microstructure of in situ SiC/Al composites

In this work, the in situ SiC/Al composites were successfully fabricated by the method of combustion synthesis and hot press consolidation in an Al-C-Si system. The effect of alloying elements (Mn, Zn, Ti) on the phase constitution and microstructure of in situ SiC/Al composites were investigated. Results indicated that the Al11Mn14 and TixSiy phases were formed in the SiC/Al composites with the addition of Mn and Ti, respectively. By the addition of Mn, the size of the synthesized SiC particles was obviously reduced, and consequently the amount of SiC particles was increased. Meanwhile, the percentage of the submicro SiC particles increased about from 22% to 83%. However, the addition of Zn and Ti had little effect on the size of SiC particles.