Abstract The orientation dependence of hardness and modulus of ZrB2 grains were determined on a polycrystalline specimen with low porosity using Berkovich nanoindentation at room temperature. Additionally, Cube corner indentation was carried out on differently oriented grains to generate visible slip patterns, which were used to analyze slip activation. The anisotropy ratio, which is the ratio of the hardest/stiffest to the softest/most compliant orientations, was higher for hardness (∼1.3) than for modulus (∼1.1). The orientation dependence of nanohardness was described using an analytical model based on the activation of multiple slip system families. Based on literature data and the present indentation results, only the { 10 1 ¯ 0 } 〈 11 2 ¯ 0 〉 , { 10 1 ¯ 0 } [ 0001 ] and { 10 1 ¯ 0 } 〈 11 2 ¯ 3 〉 type slip system families were considered in the model. Simulations showed that none of the three slip systems by itself could describe the orientation dependence of the hardness of ZrB2. Analysis of the model in combination with the results of Cube corner indentation revealed that the experimental results can be appropriately described by the simultaneous activation of the { 10 1 ¯ 0 } [ 0001 ] and { 10 1 ¯ 0 } 〈 11 2 ¯ 3 〉 slip systems. Further analysis of the model together with first principles calculations found in the literature were used to derive the hierarchy of slip activations for ZrB2 at room temperature.

中文翻译：

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ZrB 2 陶瓷晶粒的滑移活化控制纳米硬度各向异性

摘要 在室温下使用 Berkovich 纳米压痕法在低孔隙率的多晶试样上确定 ZrB2 晶粒的硬度和模量的取向依赖性。此外，立方角压痕在不同方向的晶粒上进行，以产生可见的滑移模式，用于分析滑移激活。各向异性比，即最硬/最硬与最软/最柔顺取向的比值，硬度 (~1.3) 高于模量 (~1.1)。使用基于多个滑移系统族激活的分析模型来描述纳米硬度的方向依赖性。根据文献资料和目前的压痕结果，只有 { 10 1 ¯ 0 } 〈 11 2 ¯ 0 〉 ，{ 10 1 ¯ 0 } [ 0001 ] 和{ 10 1 ¯ 0 } 〈 11 2 ¯ 3 〉型滑移系统族被考虑在模型中。模拟表明，三个滑移系统中没有一个可以单独描述 ZrB2 硬度的取向依赖性。结合立方角压痕结果对模型进行分析表明，实验结果可以通过同时激活{10 1¯ 0 } [ 0001 ] 和{ 10 1¯ 0 } 〈 11 2 ¯ 3 〉来恰当地描述滑移系统。模型的进一步分析以及文献中的第一性原理计算被用来推导出室温下 ZrB2 的滑移激活层次。结合立方角压痕结果对模型进行分析表明，实验结果可以通过同时激活{10 1¯ 0 } [ 0001 ] 和{ 10 1¯ 0 } 〈 11 2 ¯ 3 〉来恰当地描述滑移系统。模型的进一步分析以及文献中的第一性原理计算被用来推导出室温下 ZrB2 的滑移激活层次。结合立方角压痕结果对模型进行分析表明，实验结果可以通过同时激活{10 1¯ 0 } [ 0001 ] 和{ 10 1¯ 0 } 〈 11 2 ¯ 3 〉来恰当地描述滑移系统。模型的进一步分析以及文献中的第一性原理计算被用来推导出室温下 ZrB2 的滑移激活层次。