Abstract In this work, a theoretical model is developed to address the effect of primary creep on the relationship between indentation and uniaxial creep tests. By considering the expansion of a spherical cavity in the materials following the primary creeping law, a general expression of the conversion factor is deduced during the primary creep stage. For creep tests with spherical and flat punch indenters, a closed-form formula is specified for the conversion factor that is determined by the stress exponent and hardening exponent. By further considering the difference of the critical time at the onset of steady-state creep deformation between uniaxial and indentation creep tests, it becomes available to convert the indentation creep data into uniaxial creep results during the steady-state creep stage. The rationality and accuracy of the proposed model are verified by comparing with the experimental data of Sn37Pb solder, AZ31 Mg alloy and Succinonitrile. Furthermore, the comparison with previous theoretical models indicates that the ignoring of primary creep effect could lead to the deviation of converted indentation creep data from uniaxial creep results.

中文翻译：

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一次蠕变对压痕和单轴蠕变关系的影响：一个理论模型

摘要 在这项工作中，开发了一个理论模型来解决初级蠕变对压痕和单轴蠕变试验之间关系的影响。通过考虑材料中球腔的膨胀遵循初级蠕变规律，推导出初级蠕变阶段转换因子的一般表达式。对于球形和扁平冲头压头的蠕变试验，为由应力指数和硬化指数确定的转换因子指定了一个封闭式公式。通过进一步考虑单轴和压痕蠕变试验之间稳态蠕变开始时临界时间的差异，可以将压痕蠕变数据转换为稳态蠕变阶段的单轴蠕变结果。通过与Sn37Pb焊料、AZ31镁合金和丁二腈的实验数据对比，验证了该模型的合理性和准确性。此外，与先前理论模型的比较表明，忽略初级蠕变效应可能导致转换后的压痕蠕变数据与单轴蠕变结果的偏差。