Study On The Effect Of Hot-rolled Comparameter And Aging Treatment On Microstructure And Mechanical Property Of ZrTiAlV Alloy

Zr and Zr alloys are of great importance in aerospace, Military, nuclear and chemicalindustries because of low thermal neutron absorption and density, small expansioncoefficient, adequate strength and ductility, excellent anti-irradiation and corrosionresistance. To broaden the application of Zr alloys as structural material, it is considerablynecessary to improve the performance properties of these alloys, especially the mechanicalproperties. In the present work, the effect of rolling and aging temperature on themicrostructure and mechanical properties of47Zr-45Ti-5Al-3V alloy was investigatedafter solution treatment at780/850℃.The results showed that the alloy was composed of α＋β phase at the rollingtemperature lower than700℃. As the rolling temperature increased, the amount of α phasedecreased, whereas the amount of β phase increased. When the rolling temperature washigher than700℃, the alloy was composed of single β phase. With increasing rollingtemperature, the yield strength, tensile strength and hardness sharply decreased, whereasthe elongation evidently increased. The yield strength, tensile strength and hardness in thefine-grain alloy were higher than the coarse-grain alloy at the same rolling temperature. Attemperature lower than700℃, the fracture mechanism was cleavage fracture for thespecimens solution-treated at780℃, whereas the fracture mechanism was cleavagefracture and quasi-cleavage fracture for the specimens solution-treated at850℃. Whentemperature was higher than700℃, the fracture mechanism was dimple fracture for thespecimens solution-treated at780℃and850℃.After solution treatment, hot rolling and aging treatment, the alloy consisted of α, βand ω phase. With increasing aging temperature, the amount of α and ω phase wasgradually decreased. At the same rolling and aging temperature, the amount of ω phase inthe specimen solution-treated at850℃was higher than that at780℃, which results in ahigher hardness in the coarse grains than that in the fine grains. As the aging temperatureincreased, the hardness gradually dcreased. The rolling temperature has not significantlyinfluence on the hardness of the alloy at the same aging temperature.