Nanosized SiC particle reinforced Ti6Al4V matrix composites manufactured by laser melting deposition

Abstract

In this work, in-situ (TiC+Ti5Si3)/Ti6Al4V matrix composites (TMCs) with enhanced hardness and wear performance were manufactured by laser melting deposition (LMD) via the addition of nanosized SiC powder. The microstructures of single tracks were investigated to determine the optimal parameters for LMD. Besides, the influence of the SiC content on the microstructural evolutions and mechanical properties was explored. Results demonstrate that the in-situ reaction occurs between SiC and titanium during the LMD process. In-situ TiC and Ti5Si3 were distributed uniformly at grain boundaries and titanium matrix with a full-columnar grains for 0.5 wt.% and 1.0 wt.% SiC addition. The morphology of the composites consists of equiaxed grains with a three-dimensional quasi-continuous network structure when the content of SiC increases to 1.5 wt.% and 3.0 wt.%. The hardness of the composites is 321.1, 342.3, 347.8, and 442.1 Hv with the increasing formation of reinforcements. Meanwhile, the average coefficient of friction decreases from 0.39 to 0.32 with the wear mechanism changing from abrasion to adhesive wear.

Nanosized SiC particle reinforced Ti6Al4V matrix composites manufactured by laser melting deposition