【摘要】 采用一火β区热轧和一火两相区上部温度热轧获得了片状组织的TA15ELI钛合金厚板,通过两相区900℃、930℃、950℃和β区980℃退火热处理进一步调整合金显微组织和损伤容限性能,测定了不同热处理状态下合金的显微组织特征参数和室温拉伸性能、断裂韧性、疲劳裂纹扩展速率,分析了显微组织对损伤容限性能的影响关系。研究发现:两相区退火,随着退火温度的升高,TA15ELI钛合金组织中初始β晶粒尺寸和α集束尺寸基本不变,α片平均厚度有所增加,合金强度和塑性均有所下降,da/dN降低,KIC提高;合金在β区980℃退火较两相区退火具有更好的损伤容限性能和综合性能。更多还原

【Abstract】 TA15ELI titanium alloy plate of lamellar microstructure was obtained by the 1st-fire work in the upper region of α+β phase and the 2nd-fire work in the β phase region.The microstructure and damage tolerance property were adjusted by duplex anneals at 900℃,93 0℃,and 950 ℃ in α+β phase region and single anneal at 980℃ in β region for the TA15ELI titanium alloy plate.Then,tests of room temperature tensile,fracture toughness and fatigue crack propagation rate were performed and the microstructure parameters were also measured for the TA15ELI plate in different heat-treatment conditions.The experimental results showed that with the increasing of anneal temperature in α+β phase region;the thickness of α lamella increased while the size of β grains and α-colonies remained constant.At the same time for the TA15ELI plate,the strength,plasticity and fatigue crack propagation rate decreased,and the fracture toughness increased.However,the damage tolerance property and comprehensive property of TA15ELI were better than those annealing in α+β phase field if annealing at 980 ℃ in β phase field.更多还原