摘要
在加载速率500~6000 uN/s和峰值载荷4000~12000 uN的条件下进行纳米压痕蠕变实验,研究DD407镍基单晶高温合金在室温下的蠕变行为。结果表明:DD407镍基单晶高温合金具有良好的蠕变抗力性能,但其蠕变性能对加载速率和峰值载荷敏感。依据Findley模型,得到拟合的蠕变参数随着加载速率和峰值载荷的增加而显著增加,并通过计算蠕变应力指数得到合金的蠕变机理由位错控制。此外,在纳米压痕蠕变实验中发现DD407合金的硬度和模量随着加载速率和峰值载荷的增加而降低,并通过无量纲分析得到加载速率对蠕变性能的影响大于峰值载荷对蠕变性能的影响。
Nanoindentation experiments were conducted under loading rates of 500–6000μN/s and applied peak loads of 4000-12000μN to measure the creep behavior of DD407 Ni-base single crystal superalloy at room temperature.Experimental results demonstrated that DD407 Ni-base single crystal superalloy had a good creep resistance,but its creep properties were sensitive to the loading rate and peak load.The fitting creep parameters significantly increased with increasing loading rate and peak load based on the Findley’s model,and the corresponding creep mechanism was governed by dislocation based on the calculation of creep stress exponent.During nanoindentation creep tests,it was found that the hardness and reduced modulus decreased with increasing the loading rate and peak load,and through a dimensionless analysis,it was also noted that the effect of the dimensionless loading rate was stronger than that of dimensionless peak load on the creep properties.
作者
张震男
李云丽
吴文平
Zhen-nan ZHANG;Yun-li LI;Wen-ping WU(Department of Engineering Mechanics,School of Civil Engineering,Wuhan University,Wuhan 430072,China;School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan 430074,China;State Key Laboratory of Water Resources&Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)
基金
financial supports from the National Natural Science Foundation of China(Nos.11772236,11472195)。
