Corning Incorporated
Glass, glass-ceramic and ceramic articles with protective coatings having hardness and toughness

Abstract:

An article includes: a transparent substrate having a primary surface; and a protective film disposed on the primary surface, such that each of the substrate and the protective film have an optical transmittance of 20% or more in the visible spectrum, and such that the protective film includes at least one of: (1) a hardness of greater than 13 GPa, as measured by a Berkovich nanoindenter, or (2) an effective fracture toughness (Kc) of greater than 2.5 MPam.sup.1/2, as measured by indentation fracture at a depth of greater than 1 .mu.m.