Tool tip arc measurement and characterization of micro-arc diamond tools

To measure and characterize the tool tip arc of micro-arc diamond tools, an evaluation method based on high resolution scanning electron microscope image was brought out, and the edge extraction, edge fitting and the roundness characterization algorithms were also discussed. Firstly, Canny edge extraction method was adopted to detect the 2D edge profile of tool tip and moving least square algorithm was used to smooth edge profile. After that the arc characterization model of tool tip was established, and the characterization model was solved using sequential quadratic programming method. Finally, the factors affecting tool tip arc characterization results were analyzed including profile fitting error and nonper-pendicularity error, and the uncertainties of tool tip radius and tool tip roundness were also calculated. Experimental results show that the tool tip radius of micro-arc diamond tools is 30.213 μm with the uncertainty of 351 nm; the roundness is 0.114 μm with the uncertainty of 24 nm. From the characterization results it can be seen that the proposed method can measure and characterize the tool tip arc of micro-arc diamond tools with nano-meter precision.