Abstract In this article, a series of molecular dynamics (MD) simulations were performed to investigate the impacts of indentation size, grain size and temperature on the mechanical properties of polycrystalline α -quartz under quasi-static nanoindentation with conical indenter. Results from MD simulations show that the hardness and Young’s modulus are more sensitive to the temperature and penetration depth than grain size. Von Mises shear strain and the volumetric strain were calculated to depict the plastic deformation and it was found that plastic deformation becomes more dominate at higher temperatures and indentation sizes for polycrystalline α-quartz. The deformation mechanism is dominated by the grain boundary sliding instead of intragranular dislocation control at small grain size ( α -quartz under nanoindentation tests, which helps to uncover the mechanism of polycrystalline solids breakage and deformation under various conditions.

中文翻译：

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温度和晶粒尺寸对多晶石英力学性能的影响

摘要 本文通过一系列分子动力学（MD）模拟研究了压痕尺寸、晶粒尺寸和温度对锥形压头准静态纳米压痕下多晶α-石英力学性能的影响。MD 模拟结果表明，与晶粒尺寸相比，硬度和杨氏模量对温度和渗透深度更敏感。计算了 Von Mises 剪切应变和体积应变来描述塑性变形，并且发现塑性变形在多晶 α-石英的更高温度和压痕尺寸下变得更加占主导地位。变形机制以晶界滑动为主，而不是在小晶粒尺寸（纳米压痕测试下的α-石英，