Microstructure and mechanical properties of AlCoCrFeMnNi HEAs fabricated by selective laser melting

To avoid the formation of cracks and to improve the forming capability and performance of the AlCoCrFeNi high entropy alloy (HEA), equiatomic CoCrFeNiMn HEA was added into equiatomic AlCoCrFeNi HEA to form a novel AlCoCrFeMnNi HEA. Three different compositions were prepared by the selective laser melting (SLM) technique, and their formability, microstructure, and mechanical properties were analyzed. Results revealed that AlCoCrFeMnNi shows a composite-like dual-phase structure composed of a soft FCC phase and hard BCC (A2/B2) phase. With the decrease of Al, the SLM forming capability is improved. Besides, the volume fraction of the phase and the nano-hardness decreases with decreasing Al content.