Abstract Orientation-dependent irradiation hardening phenomena in pure Zr have been studied, and the corresponding mechanisms investigated based on the combined use of SEM, TEM, and CPFEM. Nanoindentation was conducted on ten grains at room temperature before and after ion irradiation (0.3 dpa, 250 °C). The hardness decreases as the declination angle (the angle between c-axis and sample surface normal) increases, both before and after irradiation. However, the irradiation induced maximum absolute and relative increment of hardness occur when the declination angle is about 55° and 60°, respectively. The hardness increment was found to be proportional to the relative activation of the type slip with increase of declination angle, at low angles. However for angles higher than 55–60° the hardness increment was found to be reduced by the activation of deformation twinning and cross slip. A peak increment of irradiation hardening is therefore observed due to the orientation-dependent combination of different deformation mechanisms. CRSS values of all slip systems and for {10–12} tension twinning before and after irradiation were obtained by fitting to a crystal plasticity finite element model (CPFEM). The obstacle strength of heavy ion induced type dislocation loops generated at 250 °C on subsequent room temperature slip was thus calculated to be approximately 0.29 ± 0.05.

中文翻译：

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通过纳米压痕、电子显微镜和晶体塑性有限元建模研究纯 Zr 中取向相关的辐照硬化

摘要 研究了纯 Zr 中取向依赖的辐照硬化现象，并基于 SEM、TEM 和 CPFEM 的联合使用研究了相应的机制。在离子照射之前和之后（0.3 dpa，250°C），在室温下对十个晶粒进行纳米压痕。在照射前后，硬度随着偏角（c 轴与样品表面法线之间的角度）的增加而降低。然而，当偏角分别约为 55°和 60°时，辐照引起的硬度绝对和相对增量最大。发现硬度增量与在低倾角下随着偏角增加而类型滑移的相对激活成正比。然而，对于高于 55-60° 的角度，发现由于变形孪晶和横向滑移的激活而降低了硬度增量。由于不同变形机制的取向相关组合，因此观察到辐照硬化的峰值增量。通过拟合晶体塑性有限元模型 (CPFEM) 获得所有滑移系统和辐照前后 {10-12} 张力孪晶的 CRSS 值。因此，计算出在 250°C 下产生的重离子诱导型位错环在随后的室温滑动中的障碍强度约为 0.29 ± 0.05。通过拟合晶体塑性有限元模型 (CPFEM) 获得所有滑移系统和辐照前后 {10-12} 张力孪晶的 CRSS 值。因此，计算出在 250°C 下产生的重离子诱导型位错环在随后的室温滑动中的障碍强度约为 0.29 ± 0.05。通过拟合晶体塑性有限元模型 (CPFEM) 获得所有滑移系统和辐照前后 {10-12} 张力孪晶的 CRSS 值。因此，计算出在 250°C 下产生的重离子诱导型位错环在随后的室温滑动中的障碍强度约为 0.29 ± 0.05。