Understanding the mechanical properties of α-quartz is of vital importance to rock engineering because α-quartz is the main component of igneous, metamorphic and sedimentary rocks. Molecular dynamics simulations (MDs) of nanoindentation tests on α-quartz were performed to investigate the effects of indenter tip radius and penetration depth on the mechanical properties of α-quartz. Indentation load-penetration depth (P-h) curves were plotted, from which Reduced Young’s modulus ($E_r)$, hardness ($\text{H})$were obtained and these mechanical parameters were then compared with the laboratory nanoindentation results. The mechanical results obtained from MDs are in good agreement with the experimental values. It can be found that $E_r$ and $\text{H}$ increase with indentation depth at shallow contact depth while they decrease with indenter tip size. To the authors’ knowledge, this is the first MDs of nanoindentation test of hard rock-forming minerals reported and we believe that this study can shed light on the precise measurement of the mechanical properties of rock minerals at micro- and nano-scales.

了解α-石英的力学特性对岩石工程至关重要，因为α-石英是火成岩、变质岩和沉积岩的主要成分。进行了 α-石英纳米压痕测试的分子动力学模拟 (MD)，以研究压头尖端半径和穿透深度对 α-石英机械性能的影响。绘制了压痕载荷 - 穿透深度 (Ph) 曲线，从中降低了杨氏模量 (${乙}_r)$, 硬度 ($\text{H})$获得，然后将这些机械参数与实验室纳米压痕结果进行比较。从 MD 获得的力学结果与实验值非常吻合。可以发现${乙}_r$ 和 $\text{H}$在浅接触深度处随着压痕深度增加而随着压头尖端尺寸减小。据作者所知，这是首次报道的硬岩形成矿物纳米压痕测试的 MD，我们相信这项研究可以为在微米和纳米尺度上精确测量岩石矿物的力学性能提供启示。