Investigation of Failure Mechanisms and Binder Performance in PCD Dies for High-Speed Copper Wire Drawing
Optimizing the service life of polycrystalline diamond (PCD) dies remains a critical challenge in high-speed copper wire drawing, particularly as operational speeds reach industrial levels of 300 m/min. This study investigates the premature failure of these dies, focusing on how binder chemistry and localized thermal effects influence the onset of “copper pickup” and subsequent fracture. Through SEM and EDS analysis of three commercial PCD grades (designated as Grade X, Grade Y, Grade Z), a significant correlation was observed between the binder′s elemental distribution and the die′s resistance to degradation. A notable enrichment of cobalt at the wearing surface (increasing from approximately 7% to 17% suggesting binder enrichment) was identified in the highest-performing dies, suggesting a potential stabilizing effect during high-speed operation. Conversely, the presence of localized oxygen and silicon concentrations within the die nib appears to facilitate brittle fracture when flash temperatures exceed 210°С. These findings provide practical insights for selecting binder chemistries and refining lubricant strategies to improve die longevity in demanding industrial environment.