Patent ID: 6311538
Filing Date: 2001-11-06
Classification: G01N

Abstract:
A method for inducing cracks of controlled size in a brittle coating of a metal test plate, said metal test plate having a surface with a brittle coating and a back surface, said process comprising:placing said test plate with its surface with a brittle coating against a backing, said backing having an area of known resistance, said area of known resistance being positioned against a first area of said surface with a brittle coating which is to have controlled cracks and which is opposite a potential cratered center on said back surface;moving a point of a penetrating tool into contact with said potential cratered center on said back surface;forcing the point of said penetrating tool into the potential cratered center on said back surface to a controlled, first measured depth thereby forming a crater on the back surface and inducing a plurality of controlled cracks on a first area of said surface with a brittle coating;withdrawing said point from contact with said back surface; andremoving said test plate from against said backing.