Electrical discharge truing of metal-bonded CBN wheels using single-point electrode

Industrial application of superabrasive metallic-bond form-wheels is currently limited by problems arising when trying to recover geometrical accuracy after precision is lost due to wear. Literature shows this is a current field of research, and different configurations of the electrical discharge dressing process can be found. In this work an original method for form truing of metal bonded cubic boron nitride (CBN) form wheels is presented for the first time in literature. The method uses a single-point metallic electrode, thus eliminating the need for expensive form electrodes. A mathematical model was derived to predict electrode path and velocity. The model includes the effect of electrode wear. Experimental tests were carried out on a test bench, showing over 90% efficiency in the removal of material from the wheel surface. Wheel performance after truing was examined through grinding tests.