Microstructure and Properties of Non-Equiatomic Ni10Cr6WFe9TiAlx High-Entropy Alloys Combined with High Strength and Toughness

Abstract

High-entropy alloys (HEAs) with excellent mechanical properties have broad application scope and application prospects. However, it is difficult to obtain the optimized element composition, based on the traditional equiatomic or near-equiatomic statistical analysis of the phase selection rules. The non-equiatomic HEAs have abundant constituents combination by optimizing the type and content of elements. In this study, Ni10Cr6WFe9TiAlx (x = 0, 1.0 and 1.5, at.%) HEAs were prepared by vacuum arc melting. The effect of Al content x on microstructure and mechanical properties of HEAs was systematically studied. The results show that the HEAs are composed mainly of face-centered cubic (FCC) with hexagonal Al2W phase. The increase of Al content promotes the formation of the hexagonal Al2W phase. When the Al mole content is 1.0, the Ni10Cr6WFe9TiAl HEA material has achieved superior mechanical properties. The alloy exhibited a high ultimate tensile strength of 741 MPa and a large total elongation of 46%. The improvement in the mechanical properties of the Ni10Cr6WFe9TiAl HEA is mainly attributed to the precipitation strengthening of the high-density Al2W phase. This work provides a reference for the future design of Al2W precipitation-strengthened non-equiatomic HEAs with ideal properties.

Effects of Chemical Short-Range Order and Lattice Distortion on Crack-Tip Behavior of Medium-Entropy Alloy by Atomistic Simulations

“…High-entropy alloys (HEAs), which are composed of multiple principal elements, possess special characteristics including high entropy, chemical short-range order (CSRO) and lattice distortion (LD) [1,2], and they are quite different than traditional alloys usually based on one parent metal. Due to their specific structure, HEAs exhibit excellent properties [1] such as a high strength [3][4][5], high toughness [6][7][8], corrosion resistance [9][10][11], wear resistance [12] (similar with high-alloy coating materials [13]) and outstanding self-sharpening capability [14], which make them promising candidates for applications in various fields. It is widely reported that HEAs with an FCC structure have good ductility and fracture toughness [1] and even excellent mechanical properties at low temperatures [6].…”