Deformation under nanoindents in sapphire, spinel and magnesia examined using transmission electron microscopy

摘要

Cross-sections through nanoindentions in the (001) surface of sapphire, spinel and magnesia have been examined in the transmission electron microscope. Electron-transparent sections were prepared using a focused ion beam microscope, All three recognized high-temperature slip systems were observed in sapphire, while spinel deformed in slip bands on the {111} planes, Evidence,A as obtained for slip on {111} planes in magnesia and the possibility that slip also occurs on {100} planes is discussed as an explanation of its high ratio of hardness to yield stress. [References: 22]