Experimental study on dry electrical discharge truing of metal-bonded diamond wheel

Metal-bonded diamond grinding wheel is widely used for precision grinding of hard and brittle materials with high-quality microstructures. However, it is extremely difficult to be trued into a specific shape due to its remarkable resistance property. The dry electrical discharge truing (DEDT) technique was presented in this paper as a solution to this problem and allowed for precise truing of diamond grinding wheel. Firstly, the shape accuracy of the V-tip diamond grinding wheel was characterized, and the influences of electrical discharge parameters on the root-mean-square (RMS) and peak-to-valley (PV) values were investigated. Then the electrical discharge truing parameters were also optimized. Finally, the trued V-tip grinding wheel was performed to machine micro array structures on the surface of cemented carbide (WC). Based on the experimental results, an open-circuit voltage of 25 V, an impulse frequency of 4000 Hz and a duty cycle of 50% were found to yield the maximum accuracy in V-tip form. The lowest PV and RMS values reached to 23.2 μm and 5.06 μm, respectively. Concurrently, the WC surface was efficiently machined to generate array structures featuring smooth surfaces and regular forms in the form of micro-grooves and micro-pyramids.