Evaluation of tensile property and strengthening mechanism of Zirconia reinforced molybdenum alloy

In this experiment, the nano-ZrO2 particles reinforced molybdenum alloy with excellent mechanical properties were prepared through liquid-liquid doping process, and the comparison with TZM alloy prepared by solid-solid doping process was conducted. During the liquid-liquid doping process, the ZrO2 particles ensured the dispersion of the second phase in alloy because they reached molecular-level uniformity, and the hydrothermal synthesis preparation process enabled the ZrO2 particles in alloy to reach nanometer size level. In Mo-ZrO2 alloy, the small and dispersed ZrO2 can effectively block dislocation and passivation cracks; both the room temperature and high temperature performance of Mo-1.5%ZrO2 alloy was better than that of TZM alloy. Based on the hindered recrystallization process, improved recrystallization temperature, as well as enhanced recrystallization strength thanks to the alloy pinning effect of ZrO2, the maximum tensile stress of Mo-1.5%ZrO2 alloy at 1000℃ was about 14% higher than pure molybdenum, and the maximum tensile stress of Mo-1.5%ZrO2 alloy at 1400℃ was at least 45% higher than pure molybdenum. Quantitative analysis shows that the strengthening effect of the second phase was the best during the recrystallization process.