超高强钛合金疲劳行为研究进展

Research Progress on Fatigue Behavior of Ultra-High Strength Titanium Alloys

超高强钛合金具有高比强度、高淬透性、耐损伤和优异的耐蚀性等优点,被广泛应用于飞机起落架、机身框架和紧固件等高强度结构件的制备。在实际服役过程中,这些构件常常在循环载荷的作用下发生疲劳失效,因此深入研究超高强钛合金的疲劳失效规律和失效机理,既具有重要的科学意义,又能对实际工程应用提供指导。本研究综述了目前关于超高强钛合金疲劳行为的研究,并探讨了经变形及热处理调控的微观组织对合金疲劳损伤机制的影响。具体关注了在双态和全片层组织中,α相的取向、体积分数、尺寸和分布等特征参量对合金在疲劳裂纹萌生和扩展两个阶段内的变形行为、损伤模式的作用机理。此外,还关注了超高强钛合金的疲劳性能强化手段,并对未来超高强钛合金疲劳研究方向进行了展望。

Possessing advantages of high specific strength,high harden ability and excellent corrosion resistance,ultra-high strength titanium alloys have been widely used in high-strength structural components such as landing gears,air frames and fasteners.These structural components are often subjected to cyclic loading during service,leading to fatigue failure as a common failure mode.Therefore,in-depth research on the fatigue failure behaviors and mechanisms of high-strength titanium alloys is not only of great scientific significance,but also provides important guidance for practical engineering applications.In this study,we review the existing researches on the fatigue behaviors of ultra-high strength titanium alloys,and discuss the influence of microstructure controlled by deformation and heat treatment on the fatigue damage mechanism.The effects of characteristic parameters such as orientation,content,size and distribution ofαphase in bimodal and full lamellar microstructures on the deformation behavior and damage mode during the initiation and propagation stages of fatigue cracks are specifically concerned.Additionally,we focus on fatigue strengthening processes of ultra-high strength titanium alloys and provide prospects for future research on fatigue of ultra-high strength titanium alloys.