Electronic and strain-elimination effects of solute–vacancy interaction in molybdenum

Abstract

The interaction between a solute and vacancy is crucial for the diffusion and precipitation of alloy elements and ultimately affects the creep resistance and safety of refractory molybdenum (Mo) alloys. In this work, the first-principles calculations of the interaction between solutes (5 light impurity atoms and 23 transition metal elements) and vacancies show that Mo is sensitive to all the light impurity elements, which indicates that these solutes are easy to combine with an Mo alloy and have relatively strong interaction. In most cases, the interaction between the 23 transition metal solutes and vacancy is attractive, but the interaction between solutes V, Ti, and the first-nearest vacancy is repulsive, and the interaction between the early elements in the 3d, 4d, and 5d series and the second-nearest vacancy is also repulsive. Then, we discuss the main factors that affect the solute–vacancy interaction, that is, the effects of electron and strain-elimination. Finally, a solute–vacancy interaction database based on the above effects is established, which would contribute to the research on heat- and radiation-resistant Mo alloys.