Laser deposition-additive manufacturing of in situ TiB reinforced titanium matrix composites: TiB growth and part performance

Ceramic reinforced Ti matrix composites (TMCs) have been widely used under severe friction and heavy loading conditions due to their superior properties. Among different types of ceramic reinforcements, TiB is considered as one of the most suitable ceramic reinforcement materials for TMCs because of its high strength and stiffness, excellent interfacial bonding with Ti matrix, and low induced stress. As a laser additive manufacturing process, laser deposition-additive manufacturing (LD-AM) has been successfully utilized to fabricate Ti-based materials. However, investigations on LD-AM of in situ TiB reinforced TMCs are limited. This investigation, for the first time, reports the tomography analysis of TiB reinforcement within Ti matrix and the formation of novel flower-like microstructure. The influences of reaction energy on part performance have been explored. In addition, the effects of input fabrication variables (including laser power and Z-axis increment) on part performance (including density, microhardness, and compressive properties) have been investigated, providing guidance on selection of input fabrication variables for future research.