High-performance electrical discharge sawing of hard and brittle monocrystalline silicon by electroplated diamond wire

Nowadays, the efficiency improvement of diamond wire sawing (DWS) of photovoltaic silicon through fine wire and high-speed sawing has met the development bottleneck. This paper is a change of thinking to provide a diamond wire electrical discharge sawing (DWEDS) method to integrate the machining efficiency of DWS and electrical discharge machining (EDM), which has more advantages than the current DWS method in sawing efficiency, kerf loss, wire mark, and surface uniformity. In order to evaluate the wire sawing efficiency considering the influence of wire bow and kerf width, a new method was proposed more suitable for the efficiency evaluation of DWEDS and DWS. The efficiency of DWEDS was proved better compared with EDM and DWS. The performance of DWEDS in the aspect of silicon loss is better than that of EDM and DWS as its kerf width is smaller. The discharge effect is used to reduce the wire marks caused by the physical cutting effect of DWS. The grain sawing is better for surface roughness compared with EDM. Also, it is found that the thickness of damaged layer produced by DWEDS is related to the contribution of physical cutting and discharge effect, which is significantly lower than that of EDM. Besides, the wire consumption of DWEDS is higher than that of DWS, but the reconsolidation of the diamond wire after discharged melting will expose more grains to ensure the wire cutting capability.

Automated summary

This paper introduces a diamond wire electrical discharge sawing (DWEDS) method that integrates the advantages of diamond wire sawing (DWS) and electrical discharge machining (EDM), which has higher sawing efficiency and better kerf loss, wire mark, and surface uniformity compared to current DWS method. A new method for evaluating efficiency considering wire bow and kerf width was proposed, and it was found that DWEDS has higher efficiency and better silicon loss compared to EDM and DWS.