Microstructure and property of AlTiCrFeNiCu high-entropy alloy

In this study, an AlTiCrFeNiCu high entropy alloy (HEA) was synthesized by vacuum arc furnace in high-purity argon atmosphere. The heat resistance of this HEA was investigated by using a differential scanning calorimeter (DSC) and a chamber type electric resistance furnace. The results showed that the microstructure of the as cast HEA treated at 500 °C was almost unchanged, which consisted of two kinds of BCC solid solution phases and small amount Fe2Ti. The hardness of AlTiCrFeNiCu HEA increased with treating temperature to a maximum value at 950 °C. It is found that, the content of Cu, Ni and Al decreased badly in the surface of as cast AlTiCrFeNiCu after immersed in the water solution of 5% HCl for 7 days. The compressive fracture strength of as cast AlTiCrFeNiCu HEA was 1219 MPa. The high compressive strength may owe to the solid solution strengthening from multi elements.

Research highlights
► In this study, an AlTiCrFeNiCu high entropy alloy (HEA) was synthesized by vacuum arc furnace in high-purity argon atmosphere. Research about this alloy has not been reported yet.
► Other than mixing entropy, the mixing enthalpy and vacancy forming enthalpy are firstly used to analyse the microstructure of high-entropy alloys.
► Thermal stability and compressive strength of this alloy were investigated in this paper. It is found that, the microstructure of the as-cast alloy treated at 500 °C was almost unchanged, and the compressive fracture strength of as-cast AlTiCrFeNiCu HEA was 1219 MPa.