摘要
本论文对 Ni3Al高温合金进行了 45 0℃～ 990℃热 /机械疲劳裂纹扩展行为的试验研究与宏微观分析。分别研究了相位角、保持时间、温度、频率对 Ni3Al合金裂纹扩展行为的影响。研究发现 :温度的升高和频率的降低均会加速裂纹扩展 ;同相位热 /机械疲劳裂纹扩展速率大于反相位热 /机械疲劳裂纹扩展速率 ,而且它们两者介于最大温度和最小温度的等温疲劳裂纹扩展速率之间 ;载荷保持加速裂纹扩展。在试验结果的基础之上 ,针对 Ni3Al合金建立了一个热 /机械疲劳扩展速率线性累积模型 ,并应用该模型对两个验证试验进行了检验 ,结果表明 ,该线性累积模型预测结果与试验数据吻合得很好。
In this paper,the experimental study and the analysis about the behavior of thermal mechanical fatigue (TMF) crack growth were conducted in Ni 3Al superalloy,with thermal cycle of 450℃ to 990℃.The effects of phase angle,load hold,temperature and frequency on thermal mechanical fatigue crack growth rate in Ni 3Al superalloy,respectively,were studied.A predictable model about thermal mechanical crack growth rate in Ni 3Al superalloy is proposed.The key results drawn from this study are as follows:Increasing temperature and decreasing frequency accelerate crack growth rate;The crack growth rate of in phase thermal mechanical fatigue is much larger than that of out phase thermal mechanical fatigue and both of them are between the crack growth rates of 450℃ isothermal and 990℃ isothermal tests;Load hold also accelerates crack growth.A linear summation model is proposed about thermal mechanical fatigue crack rate in Ni3Al superalloy based on these experimental results.This model is composed of cycle dependent component and time dependent component.And two proof tests were conducted to verify this model.The results predicted by this linear summation model agree well with experimental data.
出处
《航空动力学报》
EI
CAS
CSCD
北大核心
2002年第1期93-96,共4页
Journal of Aerospace Power
