A hardening model considering grain size effect for ion-irradiated polycrystals under nanoindentation
A hardening model considering grain size effect for ion-irradiated polycrystals under nanoindentation
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DOI：
10.1016/j.net.2021.03.007
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发表时间：
2021-03
影响因子：
2.7
通讯作者：
Liu Kai;X. Long;Bochuan Li;Xiazi Xiao;Chao Jiang
中科院分区：
文献类型：
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作者：
Liu Kai;X. Long;Bochuan Li;Xiazi Xiao;Chao Jiang
提出了一种新的具有明显晶粒度效应的离子辐照多晶硬度随深度变化的硬化模型。模型中讨论了主要的硬化机制，包括位错、辐照缺陷和晶界的贡献。比较了硬化模型的两种版本，包括线性叠加模型和平方叠加模型。改进了一种简明的参数校准方法，根据实验获得的硬度-压痕深度曲线对模型进行了参数化。结果表明，两种模型都能很好地描述未辐照多晶的实验数据，而平方叠加模型对离子辐照材料表现得更好，因此推荐采用平方叠加模型。此外，新模型将晶粒度效应与位错硬化贡献分离，使得拟合参数的物理意义比现有的硬度分析模型更为合理。
In this work, a new hardening model is proposed for the depth-dependent hardness of ion-irradiated polycrystals with obvious grain size effect. Dominant hardening mechanisms are addressed in the model, including the contribution of dislocations, irradiation-induced defects and grain boundaries. Two versions of the hardening model are compared, including the linear and square superposition models. A succinct parameter calibration method is modified to parametrize the models based on experimentally obtained hardness vs. indentation depth curves. It is noticed that both models can well characterize the experimental data of unirradiated polycrystals; whereas, the square superposition model performs better for ion-irradiated materials, therefore, the square superposition model is recommended. In addition, the new model separates the grain size effect from the dislocation hardening contribution, which makes the physical meaning of fitted parameters more rational when compared with existing hardness analysis models.