Abstract

This paper reports the creep behavior of a nickel-based single crystal alloy and the creep fracture mechanism under high temperature and low stress was discussed. The creep curves were analyzed with the Kelvin model. The retardation spectra suggest that the involved atoms during creep need more relaxation time to achieve the viscous flow, nevertheless, the creep under the stress of 120 MPa may be caused by the mismatch of dislocation motion and visco-plastic deformation. The fracture morphologies of crept alloys indicate that the nickel base single crystal alloy presents micro-pore aggregation fracture mechanism under the condition of high temperature and low stress creep.

Graphic Abstract

中文翻译：

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高温低应力下单晶镍基合金的蠕变断裂机理

摘要

本文报道了镍基单晶合金的蠕变行为，并探讨了高温低应力下的蠕变断裂机理。使用开尔文模型分析蠕变曲线。延迟谱表明，蠕变过程中所涉及的原子需要更多的弛豫时间才能达到粘性流动，但是，位错运动和粘塑性变形的不匹配可能导致在120 MPa应力下的蠕变。蠕变合金的断裂形态表明，镍基单晶合金在高温低应力蠕变条件下呈现出微孔聚集断裂机理。

图形摘要