Grain Boundary-Mediated Reduction of Radiation Defects in Different W-Based Alloys

Grain boundaries (GBs) are believed as potent defect sinks that contribute to the radiation damage reduction of materials. The defect-GB interaction has been extensively studied in pure metals, but only a few works shed light on the influence of material component such as alloying elements. In this study, the GB-mediated reduction of radiation defects in four W-based alloys (W-Re, W-Ta, W-Mo and W-V) is systematically investigated by atomistic simulations. Quantitative results show that the defect reduction in W-based alloys is significantly decreased comparing with elementary W. The principal reason for this decrease is the presence of various micro configurations where the solute-defect binding interactions are strong. Solutes with high local stress for each atom have a positive effect on the absorption of interstitials by GB. The ability of GB to absorb interstitials is enhanced with the increasing temperature, and also the accumulation of vacancies is increased when the temperature is as high as 1200 K. The findings in this work provide useful information on the design of radiation tolerance materials.