Additive manufacturing of continuous network structures by in-situ synthesis of TiB+TiC/Ti6Al4V composite powders

Abstract

Laser melting deposition technology exhibits significant potential in manufacturing titanium matrix composite parts with complex shapes. However, the convenient and efficient introduction of reinforcements has become a challenging task. Hence, based on the principle of in-situ reaction and the idea of combining pre-alloyed powder preparation, the reinforcing phase is embedded in the alloy powder, and TiB + TiC/Ti64 composite with a three-dimensional quasi-continuous network structure distribution of the reinforcement phase is prepared by laser melting deposition. Achieving the columnar to equiaxed grains transformation of the laser additive manufacturing titanium alloy while improving the strength of the matrix. The results indicate that in-situ TiB and TiC have a positive influence on the equiaxed transformation and grain refinement of primary β-Ti grains and α grains. They also facilitate the precipitation of α-Ti with non-Burgers orientation relationships and reduce the texture strength of α-Ti. This study achieved an ultimate tensile strength of 1109 MPa with acceptable ductility, the grain refinement played a pivotal role in enhancing the strength of titanium matrix composites. Consequently, this study offered a novel approach for the structural design of additive manufactured composite materials using powder as a raw material.