Microstructure and Wear-resistant Properties of in situ TiB-TiC Reinforced Titanium Matrix Composites by Laser Deposition Manufacturing

The TiB-TiC reinforced titanium matrix composites (TMCs) were manufactured by Laser Deposition Manufacturing (LDM) technique with the ball milled TA15+B4C powders with different contents of B and C elements. The microstructure and wear-resistant properties of the prepared TMCs were studied by XRD, SEM, EDS, hardness test and wear resistance test. The results reveal that in the prepared TMCs, there are two types of reinforcement, namely the TiC reinforcement with near-equiaxed shape and the TiB reinforcement with whisker or prismatic shape. With the increase in the reinforcement content, the hardness of TMCs improves, the friction coefficient might be unchangeable and the wear mass loss increases first and then decreases. Compared with the substrate, the TMC containing 1.2 wt% boron and 0.84 wt% carbon shows better wear-resistant properties. The wear mechanism of the prepared TMCs involves the abrasive wear and a small amount of oxidation wear.