Microstructure and magnetic properties evolution of Al/CoCrFeNi nanocrystalline high-entropy alloy composite

摘要

A systematic microstructure-oriented magnetic property investigation for Al/CoCrFeNi nanocrystalline high-entropy alloys composite(nc-HEAC)is presented.In the initial state,the Al/CoCrFeNi nc-HEAC is composed of face-centered cubic(FCC)-Al,FCC-CoCrFeNi and hexagonal close-packed(HCP)-CoNi phases.High energy synchrotron radiation X-ray diffraction and high-resolution transmission electron microscopy were used to reveal the relationship between microstructure evolution and mag-netic mechanism of Al/CoCrFeNi nc-HEAC during heat treatment.At low-temperature annealing stage,the mag-netic properties are mainly contributed by the HCP-CoNi phase.With the increase of temperature,the diffusion-in-duced phase transition process including the transformation of AlCoCrFeNi HEA from FCC to BCC structure and the growth of B2 phase plays a dominant role in the magnetic properties.It was found that the magnetic properties can be effectively regulated through the control of the thermal diffusion process.The nano dual-phase thermal diffusion-induced phase transition behavior of nanocomposites pre-pared based on laser-IGC technology provides guidance for the diffusion process and microstructure evolution of two phases in composites.