NANOINDENTATION STUDY OF COARSE GRAIN ALUMINA

The nanoscale characteristics of the coarse grain alumina were studied by various nanoindentation loads with a Berkovich indenter. A significant indentation size effect (ISE) was found. Maximum hardness in the ISE region was 35 ± 3 GPa, in the non-ISE region it was 27 ± 1.5 GPa. The indentation modulus was 410 ± 15 GPa in the ISE region and 257 ± 12 GPa in the non-ISE region. The hardness of basal plane was 31.2 ± 0.8 GPa and prismatic plane was 26.9 ± 1.2 GPa. The indentation modulus was 420 ± 11 GPa for basal planes and 385 ± 13 GPa for prismatic ones.