Solvent-thermal debinding process of diamond products by powder injection molding

The small diamond molded parts were prepared via a powder injection molding technology of diamond/copper-based brazing powder. A solvent-thermal debinding process was selected to remove the binder from the diamond molded parts. The effects of the debinding temperature and time on the debinding rate were discussed, and the morphological structure was analyzed by scanning electron microscope in solvent debinding. The thermal debinding effect was investigated in H2 and N2 atmosphere, respectively. The results show that the debinding rate increases with increasing the debinding temperature and time when the solvent is heptane. The binder of 92.1% in the parts was removed at 35°C for 2.5 h, favoring the generation of the pore channels inside the parts. When the parts were heated to 600°C and held for 60 min during the thermal debinding, the binder was removed, and little faults such as bubbling, cracking and collapsing were no found in the parts. Compared to N2 atmosphere, the residual carbon was increased by 0.05% and oxygen content was decreased by 0.13% at H2 atmosphere, leading to the improvement of the wettability and the bond strength between diamonds and alloy in the sintering.