Effect of Heat Treatment on Microstructure and Properties of AlFeCoCrNiTi0.2 Htgh Entropy Alloy.

AlFeCoCrNiTi_0.2 Ugh entropy alloy was prepared by vacuum casting and annealed at 600,800 and 1 100 C respectively. The microstructure and mechanical properties of the alloy with different heat treatment temperatures were studied by means of Scanning Electron Microscopy (SEM), energy dispersive analysis(EDS), X- ray diffractometer(XRD), Nano indentation instrument and universal mechanical testing machine. The results show that the as-cast and heat-treated AlFeCoCrNiTi_0.2 High-entropy alloys are body-centered cubic structure. After heat treatment,BCC1 predicates BCC₂ phase to form a biphasic structure (primary phase BCC1 + precipitated phase BCC2). At 600 C,the hardness of the alloy is 672 HV,the plastic modulus is 655. 7 Gatha pressing depth is 283. 4 nm, the compression plasticity is 28%,and the breaking strength is 1. 75 GA. The hardness of 800 C and 1 100 C alloy decreases, manly due to the decomposition of BCC phase to form a biphasic BCC (BCC1 +BCC₂) sold solution structure, which reduces the strength of the alloy. [ABSTRACT FROM AUTHOR]