Microstructural Evolution, Mechanical Properties and Tribological Behavior of B 4 C-Reinforced Ti In Situ Composites Produced by Laser Powder Bed Fusion

Based on the advantage of rapid net-shape fabrication, laser powder bed fusion (LPBF) is utilized to process B C-reinforced Ti composites. The effect of volumetric energy density ( ) on the relative density, microstructural evolution, tensile properties and wear behaviors of B C-reinforced Ti composites were systematically investigated. The LPBF-ed samples with high relative density (>99%) can be achieved, while the pores and un-melted powders can be observed in the sample owing to the low energy input (33 J/mm ). The additive particulates B C were transformed into needle-like TiB whiskers with nano-scale while C dissolved in the Ti matrix. Fine-scale grains (