Text
Focused ion beam technique was used to analyse a crater in alumina created by the repeated nanoindentation method at a high strain rate. The cross-sectional view revealed intergranular cracks beneath the surface which are not visible on the surface of the sample. Formation of cracks was detected during measurement using the high-frequency acoustic emission method and subsequently confirmed using the FIB method.
Description
Figure: (a) A crater on the surface of an alumina sample created by repeated nanoindentation. Cross-sectional view of this crater fabricated by FIB milling (b) revealing intergranular cracks.