Microstructure, mechanical, and corrosion properties of B ₄ C/Al composites with excellent ductility fabricated by laser-directed energy deposition

Aluminum matrix boron carbide (B4C/Al) composites with moderate strength but excellent ductility are fabricated by laser-directed energy deposition (LDED) with different laser powers. The microstructural features underlying the outstanding mechanical properties of such fabricated composites have been fully explored. The mechanism of the excellent ductility without notably sacrificing strength is attributed to dislocation formation, grain refinement, and precipitation effect, which could therefore advance the state-of-art in the field of B4C/Al composites. The influence of laser power on the microstructure, mechanical, and corrosion properties is also investigated. The composite fabricated by the laser power of 1200 W has the best corrosion resistance. It is found that pitting is the primary type of corrosion of the LDED B4C/Al composites in H3BO3 solution, and it is most likely to occur at the interface between Al and B4C particles. These findings highlight that the LDED process can fabricate high-performance corrosion-resistant composites.