【摘要】 本文研究了氢含量对 Ａｌ－Ｌｉ合金８０９１－Ｔ６薄板光滑试样疲劳寿命（Ｎｆ）、变形机制和断裂模式的影响结果表明，合金的氢含量由１．０４３降低到 ０．０５３ μｇ／ｇ，变成超低氢合金， Ｎｆ提高约一倍，疲劳变形机制由切割机制转变为绕过机制，断裂模式由以穿晶脆性断裂为主转变为穿晶韧性断裂，由氢脆引起的低韧性断裂特点完全消失本文还简要地讨论了氢含量变化造成疲劳变形机制和断裂模式转变的原因．更多还原

【Abstract】 Effect of hydrogen content on the smooth specimen fatigue life (Nf), the deformation mechanism and the fracture mode of 8091-T6 Al-Li alloy sheet were studied systematically. The experimental results show that as the hydrogen content is lowered from 1.043 g/g in the received alloy to 0.053 g/g in the dehydrogenated alloy called as "extra low hydrogen alloy ", the Nf is raised by about one time. The fatigue deformation mechanism is changed from the mode of dislocation sheering phase to the Orowan looping mode, and the fracture mode is changed from main characteristic of transgranular brittle fracture to transgranular ductile fracture, the characteristic of low toughness fracture induced by hydrogen embrittlement is completely eliminated. The causes for the change of the mechanism of fatigue deformation and the fracture mode by lowering the hydrogen content is discussed briefly.更多还原