粉末高温合金FGH4095的蠕变疲劳裂纹扩展行为研究

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中图分类号：0346.1 文献标志码：A文章编号：1000-4939（2026）02-0285-10

Abstract：Sintered superalloys have been widely used in advanced aero engine parts due to their excellent high temperature mechanical properties and hot workability.Sampling tests are carried out for disc-shaped part of FGH4095.The crack growth rate curves and threshold values of FGH4095 are measured at 20°C ， （204号 530∘C ， 630‰ ，and 700‰ with stress ratios O.1 and -1 by in-situ observation method. The steady-state crack growth parameters are obtained by Paris law，and the temperature dependence of each parameter is analyzed.It is found that creep has a significant efect on crack propagation behavior. At high temperature， the slope of crack growth rate curve with stress ratio O.1 is greater than that with stress ratio-1，and threshold value with stress ratio 0.1 is no longer observable.It is also found that the crack growth performance of FGH4095 would not change monotonically with the increase of temperature，and this phenomenon is explained by the data manual.Based on the damage evolution theory，the crack growth behavior under creep-fatigue coupling damage is analyzed，the frequency dependence of crack growth rate curve and Paris law's limitation are illustrated.Based on fatigue characteristic length，this paper discusses a new method for evaluating creep-fatigue life of all kinds of crack tips （including large cracks and short cracks） using frequency-dependent crack propagation data.

Key Words：sintered superally；creep-fatigue； crack growth rate;threshold value； characteristic length

FGH4095是一种采用粉末冶金工艺制备的镍基沉淀强化型高温合金材料，因其优良的高温强度行为，在航空航天领域有广泛的应用（主要用于航空发动机的动力部件）[1-3]，其抗蠕变、抗裂纹扩展性能是保障先进发动机安全性及可靠性的重要基础。（剩余14252字）