Towards fracture mechanics of thermally sprayed metallic coatings using indentation technique for edge chipping on a micron scale

摘要

Scaling down from macroscopic dimension to the micro range is feasible for edge chipping. It can be applied on coatings considering the anisotropic properties parallel and perpendicular to the substrate surface. Based on the fact that the distance c of the fracture from the edge and the chipping force are the best criteria to characterize the edge toughness of coatings, rather than indentation depth, fracture area or energy input, the test procedure can remarkably be simplified at least for thick coatings since the distance from the indenter has not to be known exactly before chipping. The distance c can be measured after chipping by any kind of microscopic device. The edge chipping method is probably even more suitable for ceramic coatings.