Microstructure and properties of Ti/TiO2@SiC/Ti6Al4V composites by selective laser melting

In this study, Ti/TiO2 composite coatings were fabricated on SiC substrates via organic chemical reduction and magnesiothermic reduction. SiC fiber-reinforced titanium matrix composites were subsequently prepared by selective laser melting (SLM). Systematic investigations reveal that the Ti/TiO2 coatings significantly enhance interfacial compatibility between SiC and the titanium matrix, thereby strengthening interfacial bonding in Ti/ TiO2@SiC/Ti6Al4V composites. The coatings further act as effective nucleation sites, promoting accelerated grain growth and transforming the composite microstructure from fine equiaxed grains to randomly oriented acicular grains, effectively reducing material anisotropy. Enhanced interfacial integrity was shown to mitigate SiC detachment during friction processes, reducing abrasive wear and improving wear resistance, while enabling efficient load transfer for superior hardness and strength. Furthermore, the coated composites exhibited markedly improved corrosion resistance compared to their uncoated counterparts.