In this study, B 4 C/Ti composites were prepared by laser powder bed fusion (LPBF), and the effects of line energy density (LED) on the microstructure evolution, mechanical properties, and electrochemical properties of the composites were systematically investigated. The results indicate that in situ reactions between B 4 C and the Ti matrix during the LPBF process led to the formation of acicular TiB, whisker‐like TiB, and granular TiC reinforcing phases. As the LED increased from 0.15 to 0.27 J/mm, the microstructure of the composites transitioned from cellular to columnar. Within the optimal LED range of 0.18–0.24 J/mm, the composites exhibited excellent comprehensive properties: an ultimate tensile strength of 848.6 MPa, a fracture strain of 8.8%, and a uniform distribution of reinforcing phases. Electrochemical tests conducted in a 3.5 wt% NaCl solution revealed that the sample produced under optimized parameters (S3) demonstrated the best corrosion resistance, characterized by the lowest corrosion current density (2.174 × 10 −6 A/cm 2 ) and the highest polarization resistance (16 720.6 Ω cm 2 ). This research elucidates the mechanism by which LED regulates the microstructure and properties of LPBF‐fabricated B 4 C/Ti composites, providing crucial process guidelines and theoretical support for the additive manufacturing of high‐performance titanium matrix composites.
Shi et al. (Sun,) studied this question.