Experimental study on the wire electrical discharge machining of PCD with different grain sizes

Polycrystalline diamond (PCD), known for its high hardness and wear resistance, is widely used as various cutting tools. As extremely difficult to machine materials, the wire electrical discharge machining (WEDM) is widely applied to cut PCD material. In this work, the material removal mechanism during WEDM of PCD materials is studied and the effect of grain size of PCD materials on WEDM performance is further analyzed. The results indicate that the material removal rate tends to decrease with the increase of grain size. The PCD materials with smaller grain size can effectively reduce the cutting difficulty, and the highest material rate can reach 1.769 mm3/min. Additionally, the cutting surface roughness of three PCD composites was affected by the grain size. The medium grain is prone to surface degradation during machining, resulting in the worst surface quality. The surface roughness of the medium grain PCD material was 67.51 % higher than that of the fine grain. Finally, the effect on the depth of the electro-erosion layer was further observed and analyzed. The overall average depth of the electro-etched layer for PCD materials with fine grain size reached the lowest 0.007 mm. These results provide theoretical support for the WEDM process of PCD materials, which contributes to improve machining efficiency and product quality.