Mechanical performance of the AlxCoCrCuFeNi high-entropy alloy system with multiprincipal elements

The AlxCoCrCuFeNi alloys with multiprincipal elements (x = the aluminum content in molar ratio, from 0 to 3.0) were synthesized using a well-developed arc-melting and casting method, and their mechanical properties were investigated. These alloys exhibited promising mechanical properties, including excellent elevated-temperature strength and good wear resistance. With the addition of aluminum from x = 0 to 3.0, the hardness of the alloys increased from HV 133 to 655, mainly attributed to the increased portion of strong bee phase to ductile fcc phase, both of which were strengthened by the solid solution of aluminum atoms and the precipitation of nanophases. The alloys exhibited superior high-temperature strengths up to 800 DGC, among which the Al0.5CoCrCuFeNi alloy, especially, had enhanced plasticity and a large strain-hardening capacity. Moreover, the wear resistance of these alloys was similar to that of ferrous alloys at the same hardness level, while the alloys with lower hardness exhibited relatively higher resistance because of their large strain-hardening capacity.