School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, People's Republic of China.
Nanoscale Res Lett. 2013 Jun 1;8(1):261. doi: 10.1186/1556-276X-8-261.
Nanoindentation tests were performed on nanostructured transparent magnesium aluminate (MgAl2O4) ceramics to determine their mechanical properties. These tests were carried out on samples at different applied loads ranging from 300 to 9,000 μN. The elastic recovery for nanostructured transparent MgAl2O4 ceramics at different applied loads was derived from the force-depth data. The results reveal a remarkable enhancement in plastic deformation as the applied load increases from 300 to 9,000 μN. After the nanoindetation tests, scanning probe microscope images show no cracking in nanostructured transparent MgAl2O4 ceramics, which confirms the absence of any cracks and fractures around the indentation. Interestingly, the flow of the material along the edges of indent impressions is clearly presented, which is attributed to the dislocation introduced. High-resolution transmission electron microscopy observation indicates the presence of dislocations along the grain boundary, suggesting that the generation and interaction of dislocations play an important role in the plastic deformation of nanostructured transparent ceramics. Finally, the experimentally measured hardness and Young's modulus, as derived from the load-displacement data, are as high as 31.7 and 314 GPa, respectively.
对纳米结构透明镁铝尖晶石（MgAl2O4）陶瓷进行了纳米压痕测试，以确定其力学性能。这些测试是在不同的施加负载下进行的，范围从 300 到 9000 μN。从力-深度数据中得出了纳米结构透明 MgAl2O4 陶瓷在不同施加负载下的弹性恢复。结果表明，随着施加负载从 300 增加到 9000 μN，塑性变形显著增强。纳米压痕测试后，扫描探针显微镜图像显示纳米结构透明 MgAl2O4 陶瓷中没有出现裂纹，这证实了压痕周围没有任何裂纹和断裂。有趣的是，材料沿着压痕边缘的流动清晰可见，这归因于位错的引入。高分辨率透射电子显微镜观察表明，晶界处存在位错，表明位错的产生和相互作用在纳米结构透明陶瓷的塑性变形中起着重要作用。最后，根据载荷-位移数据得出的实验测量硬度和杨氏模量分别高达 31.7 和 314 GPa。
