Ion Beam Sharpening of a Diamond Knife without Facet and Ripple Formation by Swinging It

Abstract

Diamond is considered a promising candidate for the source material of various small scale mechanical tools and electro-mechanical and optical devices. Usually, the diamond tools are fabricated by conventional mechanical lapping method using fine diamond powder, and a lap-plate of soft material. But, these processes can cause micro-chipping in the cutting edges and hence they are not recommendable. FIB (focused ion beam) machining is found more effective for ultra-fine machining of diamond tools but in this process formation of ripples, high damage layer, slow processing and high running cost are some major drawbacks. In order to overcome these limitations, we applied low energy ion beam machining (IBM) using broad ion beam for the sharpening of diamond knife at normal ion incidence and fixed tilt angles. However, formation of facet and/or ripples becomes problematic in this case and the possible machining conditions such as ion beam energy and tilt angle of the tools are very limited. In order to broaden the possible machining conditions as well as get facet and ripple free sharp diamond knife, we proposed swinging of the sample during ion beam sputtering process. To understand the swinging effects on diamond knife, we at first conducted experiment on flat diamond substrates by sequential sharpening process with varying angle of ion incidence. We also developed a simulation method for predicting the profile changes of diamond tools due to IBM at different swing angles. From our experiment and simulation we found, we can get very smooth and sharp diamond knife at the swing angle of ± 30°. [DOI: 10.1380/ejssnt.2012.210]