Effect of Aging Treatment on Microstructure and Mechanical Properties of Al0.7CoCrFeNi High Entropy Alloy

In this study, the effects of aging times and temperatures on microstructure, hardness compression strength Al0.7CoCrFeNi high entropy alloy have been investigated. The was cast in a vacuum induction melting furnace, homogenized at 1250 ˚C for 6 h; then aged 700 to 1000˚C 2-8 h. as-cast structure is dendritic includes FCC(A1) BCC(A2, B2) phases with 497 HV. During ageing, B2 precipitates grain boundaries 700˚C increases about 7%. ratio BCC FCC basis XRD approximately equal which increased by ageing 700˚C. At 800˚C, formation destructive hard phase σ cause 543 HV (A2+B2)/A1 has decreased. 1000 ˚C, (A2+ B2)/A1 increases, peak intensity decreases, so that value decreases 385 results hot deformation test showed strain rate 10-3 s-1 800, 900, 1100˚C yield 306, 179, 91 50 MPa, respectively.