Microstructure and mechanical properties of SiC nanowires reinforced titanium matrix composites

In order to improve the mechanical properties of Ti materials, SiC nanowires (SiCNWs) as reinforcement phase were added into Ti matrix. The SiCNWs reinforced Ti matrix (SiCNWs/Ti) composites were prepared by spark plasma sintering method. The effect of SiCNWs content on the microstructure and mechanical properties of the composites was investigated. The average grain size of Ti matrix in the composites decreased significantly compared with that of pure Ti after introducing SiCNWs due to grain refinment strengthening effect. XRD and TEM analysis results reveal that SiCNWs were closely bound to Ti matrix, and no reaction production was formed between them in the composites, indicating that the structural integrity of SiCNWs in the composites was preserved after sintering. The ultimate tensile strength of SiCNWs/Ti composites increases at first and then decreases with an increase of weight fraction of SiCNWs. Compared with the pure Ti, the tensile strength of the SiCNWs/Ti composites containing 0.50 wt% SiCNWs increased by 52%. The excellent tensile strength of the SiCNWs/Ti composites was mainly attributed to the grain refinement of Ti matrix, bridging, pullout and breaking of the SiCNWs. (C) 2019 Elsevier B.V. All rights reserved.