PCD tool welding for PCD tool preparation, PCD composite plate and carbide or steel matrix welding is very important.
PCD welding methods include laser welding, vacuum diffusion welding, vacuum brazing, high frequency induction brazing, etc.The brazing technology of PCD composite chip is one of the key technologies restricting the popularization and application of PCD tool.As is known to all, the brazing of cemented carbide mostly adopts high temperature brazing process (brazing temperature is about 1000°), while the PCD composite piece must adopt low temperature brazing process, otherwise it will cause thermal damage to the PCD composite piece, affecting its cutting performance.However, the joint strength of low temperature brazing is often lower, and it is easy to unsolder during tool processing.At present, many tool manufacturers in China are troubled by the thermal damage of PCD tool welding and the problem of unwelding.Many researchers have also made in-depth studies on this problem. In the research on high-frequency induction brazing technology of PCD composite chip, it is found that the welding temperature has the greatest influence on the welding strength when PCD composite chip is welded by high-frequency induction brazing.Through the study on the thermal stability of PCD composite plates, the safety degree of brazing was determined: when brazing SYNDITE PCD composite plates in air atmosphere, the safety temperature of CTB002 brand should be lower than 650°C, CTB010 brand should be lower than 670°C, and CTB025 brand should be lower than 720°C.In addition, wc-based cemented carbide with high cobalt content (i.e. K cemented carbide) should be preferred for brazing PCD composite chips, which is conducive to improving brazing strength.