ABSTRACT
Sputtered ceramic (metal nitride and metal oxide) thin films are widely used in coated glass products, e.g., heat reflecting glass, low-E glass and transparent con ductive glass. The mechanical durability of these films is of importance since it affects production, life time and function. The goal of industrial research is to obtain thin film products with high mechanical durability. Figure 1 shows a schematic diagram for investigations of mechanical properties of thin films. The thin film products undergo mechanical degradation in various ways in actual us age and the accelerated tests for evaluating actual mechanical durability are used, such as the Taber abrasion test[l] and the sand drop test[2]. The mechanical dura bility is supposed to be affected by the following factors: adhesion strength, coef ficient of friction and hardness of thin films, depending on the conditions in which the products are used. In turn, the basic properties of thin films, e. g., inter nal stress, bulk modulus, surface morphology, crystal structure, etc., affect these three factors. The important problems to be investigated in this diagram are l)mechanism of degradation by the accelerated tests, 2 )effects of adhesion
strength, coefficient of friction and hardness on the actual mechanical durability, 3)mechanisms of adhesion and friction, 4)effects of basic properties on adhesion strength, coefficient of friction and hardness, and 5)mutual influences of adhesion strength, coefficient of friction and hardness, on each other. We have investigated the mechanical properties of sputtered thin films on glass from such viewpoints[310]. The present paper focuses on the mechanism of adhesion and the mechanism of abrasion using the accelerated test and the effects of adhesion, friction and hardness on the abrasion.
