Fatigue Properties of Borosilicate Glass Coated with Two-Layered Ceramic Thin Films

The long-term durability of ceramics coated glass with high performance should be appropriately evaluated prior to their applications. Fatigue properties of such materials should be clarified to ensure the long-term durability. In this work, a borosilicate glass was coated with single- and two-layered ceramic thin films by a sputtering method. Fatigue tests of coated glass were conducted under bending mode, and fatigue properties of coated glass were investigated. It was revealed that the fatigue life of glass coated with two-layered film became longer compared with those of glass substrate and glass coated single-layered film. Hardness as surface characteristics of coated films, and bending strength as bulk property of coated glass were correlated with the average fatigue life, though no good correlation was found between them. Fatigue resistance strength was proposed as another strength parameter. It was found that the average fatigue life was adequately expressed by a power function of fatigue resistance strength.