Influence of Heterogeneous Microstructure on Strength of Aluminum Bronze Fabricated by Laser Powder Bed Fusion

In this research, the microstructure and tensile properties of Cu–2–7 mass% Al alloys in the α single-phase region on the phase diagram fabricated by laser powder bed fusion (PBF-LB) process and casting were systematically examined, and their microstructure formation mechanism and strengthening mechanism were investigated. As a result, the micro-fine cellular structures formed by segregation of Al due to the constitutional supercooling by rapid solidification phenomenon in PBF-LB process leaded to high tensile strength and 0.2% proof stress, which were much higher than those of the castings. It was revealed that the high performance of the Cu–Al alloys in α single-phase region is attributed to heterogeneous microstructure of the alloys formed by rapid solidification phenomenon in PBF-LB process.