Effect of impurities on elastic properties and grain boundary strength of vanadium：A first principles study

During the processing of vanadium, the inevitable incorporation of impurities can exert a significant influence on the mechanical properties. In this work, the effects of common impurity elements (H, C, N, O, Al, Cr and Fe) on elastic properties and V ∑3(111) grain boundary strength were studied by first-principles calculations. The results show that the H, C, N, O and Al elements can improve the deformation resistance but reduce the ductility of vanadium, whereas Fe exhibit the opposite effect. Electronic structure analysis provided a reasonable explanation for the observed changes in elastic properties. Then, first-principles-based tensile tests were carried out on vanadium grain boundary with impurities. The findings demonstrate that C enhances the tensile strength of vanadium grain boundary by improving the weakest bonds between adjacent V atoms. Conversely, the detrimental effect of O was attributed to the reduction of interaction between V atoms. This study contributes to a better knowledge of the potential positive and negative impacts of impurities on the mechanical properties of vanadium and provides valuable insights for future research in materials processing.