Laser power bed fusion of TiB2/Cu composite: Densification, microstructure, and properties

Abstract

Laser powder bed fusion (LPBF) technology has significantly grown to fabricate copper-based material with high degree of control over geometry. The addition of ceramic particles in LPBF of Cu has recently become a promising method for increasing processability and strength while maintaining high conductivity. The work herein produces a high strength and high conductivity Cu composite reinforced by 2 wt% TiB₂ reinforcing particles using LPBF. Adding TiB₂ reinforcing particles could eliminate unmelted powder and cracks, achieving a high relative density of 99 %. Unlike the LPBF of pure Cu with an equiaxed-columnar bimodal grain structure, the TiB₂/Cu composite presents a fully coarse columnar grain. TiB₂ particles are uniformly distributed within the Cu matrix and provide strengthening contribution of 111 MPa. Compared to the LPBF-fabricated pure Cu, the TiB₂/Cu composite exhibits a superior combination of strength (∼298 MPa) and electrical conductivity (∼78 % IACS).