Effect of SiC nano-particles on microstructure and mechanical properties of the CoCrFeMnNi high entropy alloy

Novel metal matrix nanocomposites were designed exploring the CoCrFeMnNi high entropy alloy as a matrix and SiC spherical nanoparticles with a diameter of 20-50 nm as a reinforcement phase, and manufactured by mechanical alloying followed by hot isostatic sintering. After reaction at 1000 degrees C for 15 min the microstructure consisted of a matrix with a face centered solid solution of all elemental ingredients with traces of M23C6/ M7C3 carbides ( where M - Cr, Fe, Co), s-phase and SiC nano-particles distributed along grain boundaries of the matrix. Additions of 5 wt% of SiC nano-particles increased the room temperature compressive yield strength of the CoCrFeMnNi base from 1180 MPa to 1480 MPa, accompanied by a decrease in compressive strength and plasticity. The results are discussed in terms of mechanisms controlling the strengthening process in nano-composites with high entropy alloy matrix. Crown Copyright (C) 2017 Published by Elsevier B.V. All rights reserved.