Microstructure and mechanical properties of SiC reinforced AlSi10Mg composites fabricated by laser metal deposition

Abstract

Abstract In this study, SiC/AlSi10Mg aluminum matrix composites (AMCs) were fabricated by laser metal deposition (LMD), and the effects of SiC content on microstructure, microhardness, wear performance and tensile properties were investigated. After LMD processing, the diffraction angle of the highest diffraction peak of the α-Al phase changed from 38.470° to 44.833°, demonstrating a clear preferred orientation. Si and Mg elements gathered at the grain boundaries in form of Si and Mg2Si phases. The presence of SiC promoted the aggregation of Fe elements, forming the needle-like Al-Fe-Si eutectic phase. As the SiC content increased, the grain size of the middle area decreased and the randomness of the texture distribution increased. Furthermore, the AMCs with 2wt.% SiC exhibited impressive comprehensive performances, i.e., microhardness of 117.06 HV, a wear rate of 1.84×10−3 mm3N-1m-1 and tensile strength of 219.04MPa. The wear resistance was improved and the wear mechanism changed from adhesive wear to abrasive wear with the addition of SiC participles.