ABSTRACT Brittle rupture during creep of materials is due to the formation and evolution of inter-granular cavities. Creep cavity nucleation rates – contrary to growth rates – are unpredictable, thus hindering forecasts about the lifespan of any material/specimen under creep. Via rigorous theoretical calculation, it is shown that creep cavity nucleation rates are linked to the Monkman–Grant ductility and that they can be quantitatively estimated through this link. Hence, a relevant phenomenological formula is verified, and creep-induced material-porosity estimations become achievable which in turn lead to improved predictions of rupture times or strains or other possible creep-porosity-related material properties like elastic moduli, thermal and electrical conductivities.

中文翻译：

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Monkman-Grant 延展性在蠕变空腔形核中的关键作用

摘要材料蠕变过程中的脆性破裂是由于晶间空腔的形成和演变。蠕变空腔成核率——与增长率相反——是不可预测的，因此阻碍了对蠕变下任何材料/试样寿命的预测。通过严格的理论计算，表明蠕变空腔形核率与 Monkman-Grant 延展性有关，并且可以通过这种联系进行定量估计。因此，相关的现象学公式得到验证，蠕变引起的材料孔隙率估计变得可实现，这反过来又导致对破裂时间或应变或其他可能的蠕变孔隙率相关材料特性（如弹性模量、热导率和电导率）的改进预测。