Cooling Rate and Size Effect on the Microstructure and Mechanical Properties of AlCoCrFeNi High Entropy Alloy

Abstract

High entropy alloys are usually defined as the kind of alloys with at least five principle components, each component has the equi-atomic ratio or near equi-atomic ratio, and the high entropy alloys can have very high entropy of mixing, forming simple solid solution rather than many complex intermediate phases. In this paper, the size effects on the microstructure and mechanical behaviors of a high entropy alloy of AlCoCrFeNi was studied by preparing as-cast rod samples with different diameters. The alloy independent of cast diameter samples has the same phase of body centered cubic solid solution. With decreasing casting diameter, both the strength and the plasticity are increased slightly.

First demonstration of promising selective electron beam melting method for utilizing high-entropy alloys as engineering materials

“…The fracture strength was above 1,400 MPa. This value was melting was increased, the plasticity was enhanced due to the fine grains in the same AlCoCrFeNi alloy [16].…”

“…This research was conducted to demonstrate the feasibility of producing HEAs by SEBM. We selected AlCoCrFeNi, which is a fundamental system for analyzing the relationship between the microstructure and the properties of the HEA and has been studied most extensively among the HEA systems [2,[14][15][16].…”

High temperature, low neutron cross-section high-entropy alloys in the Nb-Ti-V-Zr system

“…In agreement with ASAP and CALPHAD, the three HEAs can indeed exist as single-phase BCC solid-solutions, devoid of microsegregation induced by casting. It is reasonable to conclude that the success of the homogenisation process is sensitive to the cooling-rate thereafter: diffusion kinetics − contentiously believed to be sluggish in HEAs [64,65] − are actually sufficiently fast for elements to segregate into secondary phases over short time periods [16,66,67].…”

Tensile ductility of an AlCoCrFeNi multi-phase high-entropy alloy through hot isostatic pressing (HIP) and homogenization

“…It belongs to the Al x CoCrFeNi system, which is one of the most welldeveloped and refined HEA systems [4,15,16,[30][31][32][33][34][35][36][37][38][39][40][41]. The AlCoCrFeNi alloy shows a high compressive yield stress (σ Y = 1250 MPa at room temperature and 990 MPa at 500 °C) with a reasonable compressive ductility (ε = ~ 33 % at room temperature and ~ 63 % at 500 °C) [31,42].…”