Investigation of the microstructure evolution of TiC/Ti-6Al-4V composite manufactured by laser melting deposition

Abstract

This study investigated the microstructure evolution of the TiC/Ti-6Al-4V matrix composite produced using a 1073 nm continuous wave (CW), IPG Ytterbium fibre laser. The influence of thermal gradient, overlap, and re-melting of the previous layers on the microstructure of TiC/Ti6Al4V matrix composite samples was analyzed using the scanning electron microscope (SEM). The microstructure showed that the TiC/Ti-6Al-4V composite samples are composed of undissolved TiC, in-situ TiC (eutectic TiC and primary TiC), α Ti and β Ti. While martensite microstructure was observed on the Ti-6Al-4V alloy samples. It was observed that the single-track and single-layer composite samples are consists of blocky TiC, granular eutectic TiC, chain-shaped eutectic TiC and dendritic primary TiC phases. While the cube composite sample shows granular primary TiC and dendritic primary TiC. Dendritic primary TiC is observed in all composite samples.