The effect of in-situ ZrO2 on compressive properties of molybdenum-rhenium alloys and strengthening mechanism
Qiurui Wu, Lu Yang, Zhaoning Xu, Xun Dai, Ming Shu, Shizhong Wei, Jinshu Wang
Abstract
Molybdenum-rhenium alloys has a low recrystallization temperature and insufficient high temperature strength , making it unable to serve as structural parts for a long time in high temperature environments above 1300 ℃ for a long time. ZrO 2 dispersion strengthened Mo-Re alloy was prepared by liquid-liquid doping combined with hydrogen reduction . The morphology and distribution of ZrO 2 were adjusted by liquid-liquid doping-coprecipitation-codeposition technology, with ZrO 2 dispersed in the grain of Mo-Re alloy to refine the grain. The average grain size is reduced from 14.99 μm to 8.41 μm, and the yield strength is 539 MPa, representing an increase of 16.2 %. When the strain is 43 %, the high temperature compression performance at 1400 ℃ reaches 214 MPa, which is 28.1 % higher than that of Mo-Re. The enhanced performance is attributed to the dislocation pinning of ZrO 2 and the formation of a semi-conformal interface between ZrO 2 and the matrix, which addresses the issue of weak interfacial bonding to reinforce Mo-Re alloys. It provides a new idea for the design of Mo-Re alloys structural components such as space fission reactors fuel cladding in ultra-high temperature environment.