The formation mechanism and wear behavior of TiC + Ti₃SiC₂ + Ti₅Si₃ reinforced Ti6Al4V with network microstructure fabricated by electron beam melting

Abstract

In order to improve the wear behavior of titanium alloys, in-situ synthesized TiC+Ti3SiC2+Ti5Si3 hybrid reinforced titanium matrix composites (TMCs) were fabricated with SiC reinforced Ti6Al4V matrix composites by electron beam melting. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) techniques were applied to characterize the modified microstructure. Results showed that the re-melted composites were composed of dendrite / plate-like (TiC), rods-like (Ti3SiC2) and ultrafine needle-like (Ti5Si3) reinforcements, forming a novel network structure during the melting and solidification process. The formation mechanism of the novel structures was discussed. Microhardness and wear test were carried out and the results demonstrated that modified composites exhibited improved microhardness and wear resistance.