Effect of nano-sized ZrO2 on high temperature performance of Mo-ZrO2 alloy

Abstract

Mo-ZrO2 alloys were prepared through hydrothermal synthesis and powder metallurgy process. Room temperature microstructures of these alloy plates were observed, while high temperature tensile strength and plasticity of them were tested above 1000 °C using a Gleeble-1500D thermal simulated test machine. Results have shown that ZrO2 particles were fine in the alloy and distributed at grain boundaries and within the grains. The second phase of ZrO2 particles demonstrated a pinning effect to retard recrystallization progress and thus enhance high temperature tensile stress and plasticity of the alloys effectively. Besides, the strengthening effect of the second phase in the alloy could also effectively improve its high temperature tensile stress. Under 1400 °C, maximum tensile stress of Mo-1.5%ZrO2 alloy was 1.5 times that of pure molybdenum, while the alloy plasticity also increased dramatically. The area shrinkage of Mo-1.5% ZrO2 alloy at 1400 °C was 5 times that of pure molybdenum.