A New Perspective to Understand the Effect of Loading Rate on Creep Deformation Behavior for Novel Mo_96.18Nb_3.61W_0.21 Single Crystals: Work–Energy Conversion

Molybdenum alloy single crystals with excellent creep performances are key materials for nuclear power generation components. However, there are few reported molybdenum alloy single crystals, and the research on their creep properties is limited due to the difficulty in material preparation and the huge cost in creep experiment. In this paper, room temperature creep of novel Mo_96.18Nb_3.61W_0.21 single crystals was investigated under different nanoindentation loading rates, and creep deformation behavior was analyzed from the view of work–energy conversion. With the rising of nanoindentation loading rate, work hardening was significantly enhanced, and more deformation energy was stored in the single crystals. The stored energy rapidly released in the early stage of creep, resulting in a notable increase in the creep displacement. Although the creep deformation of (110), (111), and (112) oriented single crystals was dominated by dislocation movement, yet their creep performances exhibited evident anisotropy due to the difference in atom arrangement. The (111) orientation of Mo_96.18Nb_3.61W_0.21 single crystals has the best creep resistance among the mentioned orientations according to the comprehensive analysis results on creep displacement, creep strain rate, strain rate sensitivity, and activation volume.