Mechanical heterogeneity in rocks with a nano-indentation tester

采用锥形金刚石压头的RIDER-1型纳米压痕仪可以高精度地测量加载和卸载过程中的载荷和位移。在室温和一个大气压下，以98 mN的载荷对天然石英进行了维氏压痕试验。原子力显微镜显示压痕过程中没有断裂的证据。透射电子显微镜观察表明，在压痕试验期间没有产生位错。然而，高分辨率电子显微镜显示，晶格的尖锐折痕已经发展。这些观察结果导致石英即使在室温下也会塑性变形的结论。塑性应变通过晶格褶皱机制来调节，这在本文中是首次描述。用Oliver-Pharr方法测量了石英、绿柱石和蓝闪石的杨氏模量，结果分别为14.7、37.1和46 GPa。

A nano-indentation tester (RIDER-1) with a pyramidal diamond indenter can measure the load and the displacement with a high precision during the loading and unlaoding cycle. Vickers indentation test of natural quartz were performed with a load of 98 mN at room temperature and one atmosphere. Atomic force microscopy revealed no evidence of fracturing during indentation. Transmission electron microscope observations indicate that no dislocations were generated during the indentation tests. However, high resolution electron microscopy revealed that sharp creases of crystal lattices had developed. These observations lead to the conclusion that quartz deformed plastically even at room temperature. The plastic strain was accommodated by the mechanism of lattice creasing, which is described here for the first time. Young's modulus of quartz, piedmontite and glaucophane were also measured with the Oliver-Pharr method, the results being 14.7, 37.1 and 46 GPa, respectively.