Abstract：Taylor impact test was carried out for CoCrNiSi0.3C0.048 medium entropy alloy (MEA), and a wide range of strain and strain rates with gradient distribution in the alloy was introduced. The strain and strain rate-dependent gradient microstructure distribution characteristics and evolution mechanism were investigated. With the increase of strain and strain rate, the evolution process of the primary Cr23C6 carbides is mainly the increase of cracks, crack branching and crack width. For the secondary Type-Ⅰ SiC precipitates, the evolution process is mainly the formation and propagation of cracks. However, the tertiary Type-Ⅱ SiC precipitates are mainly gradual intensification of the dislocation - bypass mechanism. In the FCC matrix, the interaction among dislocation, twins, and three-level hierarchical precipitates is intensified with the increase of strain and strain rate.
2023, Vol. 44 
