Selective laser melting of novel nanocomposites parts with enhanced tribological performance Nanocrystalline TiC/Ti nanocomposites parts were built via SLM technology and the densification, microstructures, microhardness and tribological Performance were investigated

Selective laser melting (SLM) was applied to build the nanocrystalline TiC/Ti nanocomposites parts. The influence of linear laser energy density (lambda) on densification, microstructures, microhardness, and tribological performance of SLM-processed parts was investigated. It showed that the densification rate of TiC/Ti parts remained above 97% using linear laser energy density lambda >= 600 J/m. A decrease in lambda caused the balling effect and lowered densification. The TiC reinforcement in SLM-processed parts had unique microstructures distinctly different from the initial nanoparticle morphology. A proper decrease in lambda led to the formation of the uniformly dispersed nanoscale lamellar TiC reinforcement. The SLM-processed parts had an enhanced microhardness of 566 HV0.2, a low average coefficient of friction (COF) of similar to 0.25 and a reduced wear rate of similar to 4 x 10(-16) m(3)/(Nm) during dry sliding tests. The insufficient SLM densification at a low lambda and the disappearance of nanoscale TiC reinforcement at a high lambda generally lowered the tribological performance of SLM-processed TiC/Ti parts.