In-situ preparation and formation of TiB/Ti-6Al-4V nanocomposite via laser additive manufacturing: Microstructure evolution and tribological behavior.

Abstract In this study, the in-situ synthesized TiB/Ti-6Al-4Vceramic-matrix nanocomposites with greatly enhanced hardness and wear resistant property have been prepared via selective laser melting (SLM) using a simple mixture of microsized Ti-6Al-4V and TiB 2 powders. In order to provide a valuable reference for fabricating TiB/Ti-6Al-4V parts with metallographic features, effects of reinforcement content on microstructure and mechanical properties have been systematically investigated. It is found that during SLM process, the additive particles TiB 2 are totally transformed into need-like nanoscaled TiB phase, and the microstructure of composites is composed of mutual parallel strips architecture with TiB rich in some regions but lean in the other regions. The SLM-producedTiB/Ti-6Al-4 V composites exhibit superior nanohardness of 6.0 GPa, which is much higher than its traditional sintering counterpart. Moreover, the in-site synthesized TiB reinforcement can remarkably improve in the wear resistance properties, the wear loss of TiB-free sample is approximately 2 times than that of the sample with 3 wt% TiB 2. Graphical abstract Unlabelled Image Highlights • In-situ synthesized TiB/Ti-6Al-4V nanocomposites have been prepared via SLM. • The need-like nanoscaled TiB phase formation and evolution mechanism during SLM is discussed in detail. • The interface orientation relationship between TiB and Ti matrix has been investigated. • The SLM-producedTiB/Ti-6Al-4V composites exhibit superior hardness and outstanding wear resistant property. [ABSTRACT FROM AUTHOR]