Determination of thin film hardness for a film/substrate system

A simple model for determining the film hardness for the composite hardness of a film/substrate system is developed. On the basis of volume law and cu rrent models, the model can be used without requiring any additional materi al property for amorphous, multicomponent and multiphase coatings. As the c ause of indentation size effect (ISE) is taken into account, the ISE of the film is neglected at a high depth/thickness ratio and the introduction of Meyer's equation is avoided. The hardness values of TiC/a-C:H in situ compo site films by PECVD are assessed with the model by controlling the film thi ckness and indenting under fixed loads, the results obtained for the films coated on Si(100) and Coming 7059 are 1479 and 1681 kg/mm(2) respectively. (C) 2001 Elsevier Science Ltd and Techna S.r.l. All rights reserved.