(四川大学 金属材料系， 成都 610065)
摘 要: 采用CT试样对4种含氢量不同的Ti-4Al-2V钛合金的室温疲劳裂纹扩展速率进行了实验测定， 并对断裂以后的试样进行了断口观察。实验结果表明： 含氢的Ti-4Al-2V材料的稳态裂纹扩展行为符合Paris幂律关系， 氢对裂纹稳态扩展区和失稳扩展区的da/dN基本没有影响, 但对近门槛扩展行为有明显影响； 与自然含氢量的材料相比， 高含氢量的材料疲劳裂纹在近门槛扩展区的速率明显较低。
关键字: 氢； 钛合金； 疲劳； 断口
（Department of Metallic Materials, Sichuan University, Chengdu 610065, China）
Abstract:The CT specimens of Ti-4Al-2V alloy bearing four different hydrogen contents were employed to measure the fatigue crack propagation rate at room temperature and the fracture surfaces were observed. The results reveal that the behavior of stable crack propagation is in a good accordance with the Paris Law, and the hydrogen has little effect on da/dN in stable crack propagation stage and rapid rupture stage, but has remarkable effect on da/dN in near-threshold crack growth. Compared with the material of natural hydrogen content, the materials with higher hydrogen concentration show lower crack growth rate within near-threshold stage.
Key words: hydrogen; titanium alloy; fatigue; fracture morphology
