Damping capacity and mechanical properties of Fe3Cr2NiCuAlx medium entropy alloys by tuning phase constituents

A comprehensive analysis of the phase constituent, microstructure and mechanical/damping properties of Fe3Cr2NiCuAlx (x = 0, 0.125, 0.25, 0.5) alloys by tuning the Al mole ratio is presented in the paper. The results show that the phase constitutions of the alloys are the face centered cubic (FCC) and body centered cubic (BCC) phases and the volume fractions of the two phases are changed with the Al content. For the alloys with the Al mole ratios of 0 and 0.125, the FCC phase predominates as the matrix and the FCC2 nanoparticles are precipitated in the matrix, while for the alloys with the Al mole ratios of 0.25 and 0.5, the BCC phase predominates as the matrix and the B2 nanoparticles are precipitated in the matrix. The highest damping capacity of 0.056 was found for the Fe3Cr2NiCuAl0.25 alloy with 70.1 vol% of the BCC phase in the form of the dendrites and 29.9 vol% of the FCC phase in the form of the interdendrites. This alloy also has a high yield strength of 1069 MPa with the plastic strain being over 50% without fracture under compression. (c) 2022 Elsevier B.V. All rights reserved.