含Mo单晶镍基合金的高温蠕变及损伤行为

发布时间：2019-02-27 07:51

【摘要】：通过蠕变性能测试及组织形貌观察,研究含3%和5%(质量分数)Mo无Re单晶镍基合金的高温蠕变和损伤行为。结果表明:与3%Mo单晶合金相比,5%Mo无Re单晶合金具有较好的蠕变抗力和较长的蠕变寿命,测定出5%Mo单晶合金在1040℃、137 MPa的蠕变寿命为556 h。在施加的温度和应力范围内,测定出合金在稳态蠕变期间的表观蠕变激活能Q=484.7 kJ/mol。合金在稳态蠕变期间的变形机制是位错在基体中滑移和攀移越过筏状γ′相;合金在蠕变较后阶段的变形机制是位错剪切进入筏状γ′相。随蠕变进行,位错的交替滑移致使合金中筏状γ′相发生扭曲,并在筏状γ′/γ两相界面发生裂纹的萌生和扩展,直至断裂,是合金在高温蠕变后期的损伤与断裂机制。
[Abstract]:The creep behavior and damage behavior of Re-free single crystal nickel-base alloy containing 3% and 5% Mo at high temperature were studied by means of creep test and microstructure observation. The results show that compared with 3%Mo single crystal alloy, 5%Mo single crystal alloy without Re has better creep resistance and longer creep life. The creep life of 5%Mo single crystal alloy at 1040 鈩，

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