Investigation of plastic deformation mechanism of Cu-Cr-Zr-Sc alloys via in-situ EBSD

Studying the impact of doping elements, which cause segregation at grain boundary (GBs) due to low solubility, is crucial for understanding the mechanism of plastic deformation. This study reveals the plastic deformation mechanisms of Cu-Cr-Zr-Sc alloys during tensile testing based on in-situ EBSD observations. During deformation, random orientation changes occur within the grains. The input and output slip systems on both sides of the twin boundary are symmetrical along the twin boundary. Additionally, simultaneous activation of multiple slip systems and interactions between dislocations and the second phase cause local strain variations within the grains. The Sc-rich segregation at GBs does not affect slip transfer at between adjacent grains and thus has minimal impact on the ductility. Due to the segregation enhancement of grain boundary cohesion, the crack at the grain boundary does not expand significantly even under high strain, which reflects a strong crack coordination ability. Finally, slip systems involved in slip transfer have a higher composite Schmid factor (CSF). Compared to the geometric compatibility$$factor$(m^{\prime })$, the CSF, which considers local shear stress induced by the input slip system, more accurately explains why slip systems with low Schmid factor (SF) are activated and better predicts slip transfer behavior in Cu-Cr-Zr-Sc alloys.