Microstructural control and properties optimization of high-entrop alloys

A criterion for the solid-solution phase formation in the high-entropy alloys was proposed based on two parameters Omega>1.1 and delta<6.6%. Here, Omega = T-m Delta S-mix/vertical bar Delta H-mix vertical bar , and delta = root Sigma(n)(i=1) ci(1 - ri / (r) over bar )(2). The high-entropy alloys of TiZrNb, CoCrFeNiCu, and CoFeNi(AlSi)(x) (X= 0.2, 0.5) were prepared by arc-melting and copper mold casting. It was found that the tensile yield strength of the TiZrNb alloy was 872MPa, and tensile modulus was 45GPa. The properties of CoCrFeNiCu alloys can be optimized by multiple processing, such as cold rolling, annealing, and water quenching. Based on the HE(high-entropy) conception, a soft magnetic alloy CoFeNiAlxSix was developed. (C) 2011 Published by Elsevier Ltd.