摘要
TB8(Ti-15Mo-2.7Nb-3Al-0.2Si)是一种亚稳态β型钛合金,在航空航天领域发挥着重要的作用。微观组织结构、应变和应变率是影响材料力学性能的3大重要因素,基于万能材料试验机和分离式霍普金森压杆(SHPB)测试手段,研究了固溶和时效热处理工艺对TB8钛合金力学性能的影响,并通过光学显微镜和扫描电子显微镜表征材料变形前后的微观组织结构及其断面形貌。结果表明:经过固溶+时效处理后,合金内部析出短条状α相,且时效温度越高,次生相尺寸越大,数量越少;在不同应变率加载条件下,热处理前后的TB8钛合金均表现出明显的应变率强化效应,动态加载条件下应变强化作用不明显;时效温度升高时,高应变率下合金屈服强度降低,塑性升高;动态加载条件下试样的破坏形式为典型的剪切破坏;绝热剪切带是裂纹形成和试样破坏的前兆。
TB8(Ti-15Mo-2.7Nb-3Al-0.2Si)is a metastableβtitanium alloy,which plays an important role in the aerospace field.Microstructure,strain and strain rate are three important factors affecting mechanical properties of TB8 titanium alloy.Based on a universal material testing machine and a split Hopkinson pressure bar(SHPB)device,the effect of solution and aging heat treatment process on mechanical properties of TB8 titanium alloy was studied.Optical microscope(OM)and scanning electron microscope(SEM)were used to characterize the microstructure and section morphology of the specimens before and after deformation.The results show that short stripαphase precipitates inside the alloy after solution and aging treatment,and the size and quantity of secondary phase increase with aging temperature increasing.Under different loading conditions,the strain rate strengthening effect of TB8 titanium alloy before and after heat treatment is obvious,but the strain strengthening effect is not obvious under dynamic loading condition.With the increase of aging temperature,the yield strength of the alloy decreases and the plasticity increases.The failure mode of specimens under dynamic loading is typical shear failure.Adiabatic shear band is the precursor of crack formation and specimen failure.
作者
陈稳
郭保桥
郭岩松
栾可迪
冉春
陈鹏万
CHEN Wen;GUO Baoqiao;GUO Yansong;LUAN Kedi;RAN Chun;CHEN Pengwan(State Key Laboratory of Explosion Science and Technology,Beijing Institute of Technology,Beijing 100081,China;China Ordnance Society,Beijing 100089,China)
出处
《高压物理学报》
CAS
CSCD
北大核心
2022年第5期64-74,共11页
Chinese Journal of High Pressure Physics
基金
国家自然科学基金(12072038,12102400)。
