Finishing of polycrystalline diamond tools by combining laser ablation with grinding

In manufacturing polycrystalline diamond (PCD) tools, the finishing process in order to obtain the required surface and edge quality and to remove the damaged PCD layer induced by the prior manufacturing steps is mostly done by grinding. However, grinding is currently inefficient and costly due to low material removal rates and high wear of the grinding wheel. The project "Pro-PKD" aims to increase throughput and reduce tool wear by an additional laser ablation step prior to grinding. In first process investigations, the influence of different laser parameters on the ablation rate was analyzed and an optimum parameter set for maximum ablation efficiency was found. By measuring the overall material removal from the grinding wheel and the PCD tool, it could be shown that the G-ratio can be increased by at least a factor of two. Furthermore, the time required for grinding can be significantly shortened. As the time needed for laser ablation is only several seconds, in this way the whole time required for the finishing process can be reduced. In any case, the combined process presented here has the distinct advantage that it can be implemented into already existing grinding machines with comparatively low investment costs.