High-Temperature Tensile Strength of Al10Co25Cr8Fe15Ni36Ti6 Compositionally Complex Alloy (High-Entropy Alloy)

Homogenizing at 1220A degrees C for 20 h and subsequent aging at 900A degrees C for 5 h and 50 h of a novel Al10Co25Cr8Fe15Ni36Ti6 compositionally complex alloy (high-entropy alloy) produces a microstructure consisting of an L1(2) ordered gamma' phase embedded in a face-centered cubic solid-solution gamma matrix together with needle-like B2 precipitates (NiAl). The volume fraction of gamma' phase is similar to 46% and of needle-like B2 precipitates < 5%, which is in accordance with the prediction of calculation of phase diagram method (CALPHAD using Thermo-Calc software with TTNi7 database; Thermo-Calc Software, Stockholm, Sweden). The high-temperature tensile tests were carried out at room temperature, 600A degrees C, 700A degrees C, 800A degrees C, and 1000A degrees C. The tensile strength as well as the elongation to failure of both heat-treated specimens is very high at all tested temperatures. The values of tensile strength has been compared with literature data of well-known Alloy 800H and Inconel 617, and is discussed in terms of the observed microstructure.