Evaluation of raw hardness of DLC thin films prepared by IBAD

In this study. diamond-like carbon (DLC) films were prepared by ion beam as sisted deposition (IBAD), and micro-indentation tests were performed to eva luate the raw hardness that was independent of both the film thickness and the substrate hardness. As a result, the hardness constant proportional to the square root of the product of the Vickers hardness and elastic modulus was defined by analyzing the loading curves. Then, the raw hardness of the DLC films on tungsten carbide (WC) or high-speed steel (HSS) was evaluated by using the hardness constant. The effects of ion species in IBAD and the substrates with the different hardness were discussed. It was concluded tha t the evaluation by using the hardness constant proposed in the present stu dy was useful for determination of the raw hardness of DLC films prepared b y IBAD. (C) 1999 Elsevier Science B.V. All rights reserved.