Mechanisms of sawing of BK7 glass by electrolytic in-process dressing

The electrolytic in-process dressing (ELID) was used in the sawing of BK7 glass. In the ELID process, the metal-bonded diamond saw was sharpened on site by anodic dissolution of the metal bond. The effects of normal load and current density on the efficiency of material removal, the tool wear rate and the sharpening of metal-bonded diamond saw were studied. It was found that for a given normal load, the sawing efficiency increases initially with the ELID current density and then reaches a plateau. In the plateau region, the sawing efficiency is not sensitive to the current density. If ELID operation is inside this range, a stable machining quality could be achieved. The tool wear rate during ELID was found to be separable into two parts: the mechanical wear and the anodic dissolution. The mechanical wear can be estimated from the G ratio and the anodic dissolution can be calculated from Faraday's law and the current efficiency. The current efficiency is around 0.5 (0.41-0.57) in agreement with literature.