Mechanisms of creep deformation in polycrystalline Ni-base disk superalloys
Mechanisms of creep deformation in polycrystalline Ni-base disk superalloys
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DOI：
10.1016/j.msea.2006.08.148
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发表时间：
2008-06
期刊：
影响因子：
6.4
通讯作者：
R. Unocic;G. Viswanathan;P. Sarosi;S. Karthikeyan;Ju Li;M. Mills
中科院分区：
文献类型：
--
作者：
R. Unocic;G. Viswanathan;P. Sarosi;S. Karthikeyan;Ju Li;M. Mills
本文综述了目前提出的γ′强化镍基高温合金的蠕变机制。不同的蠕变强度控制模式，如位错耦合的反相边界剪切、涉及超晶格层错的剪切构型、Orowan环、爬升旁路和微孪晶。这些都受到γ′析出相规模的强烈影响，并在特定的温度和应力范围内起作用。最近关于微孪晶和扩展层错机制的实验发现表明，这些变形模式之间存在重要的相似性。这表明，在肖克利部分之后的局部原子重排序是在这种状态下表现出温度依赖性的原因。
This paper reviews the presently proposed mechanisms for creep of γ′ strengthened Ni-base superalloys that are typically used for disk applications. Distinct creep strength controlling modes, such as dislocation-coupled antiphase-boundary shearing, shearing configurations involving superlattice stacking faults, Orowan looping, climb by-pass, and microtwinning have been observed. These are strongly influenced by the scale of the γ′ precipitating phase and are operative within specific ranges of temperature and stress. Insight from more recent experimental findings concerning microtwinning and extending stacking fault mechanisms suggest important similarities between these deformation modes. It is suggested that local atomic reordering in the wake of Shockley partials is responsible for the temperature dependence exhibited in this regime.