A Dual-Phase Multi-Functional Fenicr0.8al0.8 High Entropy Alloy with Attractive Thermal Physical Properties and Magnetic Properties

Abstract

FeNiCr0.8Al0.8 high entropy alloy with multi-functional properties combined with experimental characterization and theoretical calculation was reported and studied systematically in this work from microstructure to thermal physical and magnetic properties. It can be observed that this alloy formed a comparable fraction of two BCC phases with weave-like microstructures. This alloy exhibits fascinating multifunctional properties of near constant low thermal expansion coefficient of approximately  at a wide temperature range associated with the constitutional phase microstructure, the temperature dependence of lattice expansion, and invar effects; satisfied thermal conduction properties with thermal conductivity of up to 37.582 W·m-1·K-1 enabled by electron-phonon transportation at 1173 K than that of In600 superalloy, and acceptable magnetic response. The curie temperature of as-cast FeNiCr0.8Al0.8 alloy is determined to be 737 K. The occurrence of secondary order phase transition is further explained by the abrupt property shift of the BCC2 phase under elevated temperature, inducing the alteration of thermophysical and magnetic behavior. The magnetic transition mainly contributes to high magnetic moments and spin polarization of Fe and Ni atoms.

Keywords: high entropy alloys, Dual phase, thermal properties, Magnetic properties, first-principles calculations