Measurement of diamond conditioner microwear

Diamond wear is measured on a conditioning tool by numerical matching of interferometry images taken in overlapping areas before and after extended wear testing. The matching algorithm finds the largest common region shared by the two images and reorients the final image in space to produce the best possible match with the initial image in the binding metallization. By characterizing the images using surface height probability density functions, peaks in the height distributions can be identified that correspond to single diamonds or groups of diamonds. Shifts in the peaks after wear testing then provide an estimate of the mean wear rate. The average diamond wear rate on polyurethane was found to be about 5×10^-4 μm/min at 2 PSI nominal pressure, with higher diamonds wearing faster than shorter ones and diamonds on the outside edge of the conditioning tool wearing slightly faster than those in the center. Electron microscopy confirmed the presence of microwear. Microwear was observed to coincide with a gradual decline in pad cut rate.