Ionised cluster beams as a hardness measurement tool

Large cluster ion bombardment has been shown to be a unique tool for genera ting a variety of bombarding effects over a broad range of acceleration ene rgies. We propose to use the effects of the impact of Large gas cluster bea ms on the surface for a new hardness measurement technique. The cluster imp act leaves a crater on the surface, the size of which varies according to t he surface hardness and the cluster parameters (which can be pre-determined ). With proper calibration, this effect can be used for determination of ha rdness. Alternatively, the sputtering yield can be used for the same purpos e. These are entirely surface effects and depend on the surface material an d not on the substrate. This measurement method also eliminates the need fo r indenters that are harder than the material measured. The technique is pa rticularly useful for measuring hardness of thin film coatings deposited on softer substrates (for which no other technique is available). (C) 1999 El sevier Science B.V. All rights reserved.