(四川大學 金屬材料系， 成都 610065)
摘 要: 采用CT試樣對4種含氫量不同的Ti-4Al-2V鈦合金的室溫疲勞裂紋擴展速率進行了實驗測定， 并對斷裂以后的試樣進行了斷口觀察。實驗結(jié)果表明： 含氫的Ti-4Al-2V材料的穩(wěn)態(tài)裂紋擴展行為符合Paris冪律關(guān)系， 氫對裂紋穩(wěn)態(tài)擴展區(qū)和失穩(wěn)擴展區(qū)的da/dN基本沒有影響, 但對近門檻擴展行為有明顯影響； 與自然含氫量的材料相比， 高含氫量的材料疲勞裂紋在近門檻擴展區(qū)的速率明顯較低。
關(guān)鍵字: 氫； 鈦合金； 疲勞； 斷口
（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
