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.