Development of a Non-contact Measurement System for In-situ Tool Profile Monitoring

Single crystal diamond tool has the highest known hardness, good wear resistance, high conductivity, low in thermal expansion which makes it an ideal tool material for cutting precision diffractive optical elements, aspheric metal optical components etc. As long as tools are in use, it is only the matter of time tool will experience attritious wear, micro-fracture and eventually worn out. Since the surface roughness and form accuracy are very much depending on the sharpness and shape accuracy of the tool. Whatever is happened on the cutting edge will reflect on the workpiece. An effective and precise tool profile monitoring technique is of essential importance in ultra-precision diamond turning operation. The optical/non-contact way of tool profile monitoring has the advantage of not having to touch the tool, but its resolution is limited by the optical diffraction limit and the resolution of the CCD device used (mm/pixel). A non-contact precision tool profile monitoring system is developed and built in this study. The results showed good agreement with the profile data obtained by SEM micrographs and data measured by the precision profilometer.