Fracture behavior of high-entropy alloy coating by in-situ TEM tensile testing

Abstract

The fracture behavior of high-profile high-entropy alloy coating was characterized by in-situ TEM tensile testing. The samples for in-situ TEM tensile testing were obtained by FIB technology. The results show that irrelevant to phase constitution, the Young's module, fracture strength and ultimate elongation are measured as ∼107 GPa, ∼2.70 GPa and ∼2.6%, respectively. Transcrystalline fracture and cleavage fracture with the cleavage plane of {112} are observed evidentially and the evolution of the dislocation motion in the material could be directly connected with the fracture behavior from the recorded movies obtained by a Gatan CCD camera. The engineering stress-strain curve is nearly linearity, however, a slight deviation away from linearity could be noted in the end of engineering stress-strain curve, which is attributed that the extra elastic deformation results in part of continued deformation.