Crack-arresting compression layers produced by ion implantation

Compression layers were produced in aluminium oxide and magnesium oxide samples using high energy ion implantation. In the experiments, the samples were implanted with 3.0 MeV H+ ions to a fluence of 3.3 x 1017 cm-2 over the area of ∼3.0 cm2. The lattice expansion and compressive stress distribution with depth was measured using high resolution Raman microscopy. The implantation-induced compression layers were demonstrated to represent effective barriers for arresting the propagating cracks. Major factors that govern the crack closure, in particular the effect of ion energy and state of stress on the localization and efficiency of the implantation-induced compression layers, are discussed