(四川大學(xué) 金屬材料系， 成都 610065)
摘 要: 采用CT試樣對(duì)4種含氫量不同的Ti-4Al-2V鈦合金的室溫疲勞裂紋擴(kuò)展速率進(jìn)行了實(shí)驗(yàn)測(cè)定， 并對(duì)斷裂以后的試樣進(jìn)行了斷口觀察。實(shí)驗(yàn)結(jié)果表明： 含氫的Ti-4Al-2V材料的穩(wěn)態(tài)裂紋擴(kuò)展行為符合Paris冪律關(guān)系， 氫對(duì)裂紋穩(wěn)態(tài)擴(kuò)展區(qū)和失穩(wěn)擴(kuò)展區(qū)的da/dN基本沒有影響, 但對(duì)近門檻擴(kuò)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(kuò)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
