A high strength and high thermally stable nanostructured CoCrFeMnNi alloy prepared by high energy laser shock

Nanostructured metals generally have high strength and hardness because the internal boundaries impede the dislocation motion, providing Hall-Petch strengthening. Here, we developed a nanostructured CoCrFeMnNi high entropy alloy via high energy laser shock. A higher yield strength of 1020 MPa with an engineering plastic strain exceeds 30% was achieved at average grain size of 140 nm. In particular, the excellent stability of coherent twin boundaries (CTBs) in nanocrystalline not only has strong resistance to dislocation motion, also inhibit grain boundary migration and therefore result in outstanding grain-size thermal stability even at 1073K. Our findings provide a simple processing route to develop nanostructured CoCrFeMnNi alloy with high performances by high energy laser shock.