School of Physics and Electronics, State Key Laboratory for Powder Metallurgy, Central South University Changsha, 410083 People's Republic of China.
Nanotechnology. 2013 Jul 19;24(28):285703. doi: 10.1088/0957-4484/24/28/285703. Epub 2013 Jun 20.
An improved loop test, which consists of twisting a loop in a nanoscale whisker adhered to a transmission electron microscopy (TEM) grid or other flat substrate and pulling the ends until the loop breaks, was developed for experimentally approaching the intrinsic strength of the whisker material. Alumina whiskers with diameters in the 82-320 nm range, as test targets, exhibited an average fracture strength of 39.1 GPa with a maximum of 48.8 ± 1.8 GPa, which is close to the theoretical prediction of ∼46 GPa. In situ TEM fracture analysis demonstrated the brittle fracture of alumina whiskers with thicknesses down to 82 nm. Conventional SEM/TEM imaging induced fracture of the whisker loops that had experienced high strain and a possible mechanism were discussed.
一种改进的环形测试，包括在附着于透射电子显微镜（TEM）网格或其他平坦基底的纳米级晶须上扭曲一个环形，并拉伸两端直到环形断裂，用于实验接近晶须材料的固有强度。作为测试目标的直径在 82-320nm 范围内的氧化铝晶须，平均断裂强度为 39.1GPa，最大值为 48.8±1.8GPa，接近约 46GPa 的理论预测值。原位 TEM 断裂分析表明，厚度低至 82nm 的氧化铝晶须发生脆性断裂。讨论了经历高应变的晶须环的常规 SEM/TEM 成像诱导断裂和可能的机制。
