Dynamic Behavior of CrMnFeCoNi High-entropy Alloy

SHITENG ZHAO; YONG LIU; LI, ZEZHOU; BINFENG WANG; RITCHIE, ROBERT; MEYERS, MARC A.; RUESTES, CARLOS J.; LIAW, PETER

Conferencia; TMS 2020; 2020

High impact resistance of CrMnFeCoNi high-entropy alloy (HEA) is expected from their excellent high-strain-rate plasticity. Its underlying deformation mechanisms under dynamic loading have been identified by both experiments and simulations. The high strain-hardening ability of the CrMnFeCoNi HEA, enabled by solid-solution hardening, forest dislocation hardening and twinning hardening, a marked strain-rate sensitivity and modest thermal softening, result in an excellent resistance to shear localization. For the CrMnFeCoNi alloy, a shear strain of ~7 has been discovered as required for shear-band propagation (using a hat-shaped specimen that enables one single shear band to initiate and grow). Simultaneously, nanotwinning plays a dominant role on deformation during shock hardening (front surface) and spalling (rear surface) of the CrMnFeCoNi alloy employed on laser ablation shock compression. The remarkable high-strain-rate behavior and its deformation mechanisms makes CrMnFeCoNi HEA a significant candidate for ballistic applications.