Study on efficient electrolytic Co removal and structural properties of PDC via complexing agent regulation

In order to minimize the influence of metallic Co on the structural properties of polycrystalline diamond compact (PDC), this study employed an efficient electrolytic Co removal process to investigate the mechanism of complexing agents—Glycine (Gly), Citric Acid (CA), Tartaric Acid (TA), and Ethylene Diamine Tetraacetic Acid (EDTA)—in the electrolytic Co removal from PDC. The results show that Gly performed significantly better than CA, TA, and EDTA in Co removal from PDC. At the Gly concentration of 0.08 mol/L, the Co removal depth and Co removal rate reached 635 μm and 90.77 %, respectively, after 4 h of electrolysis. This significantly improves the efficiency of Co removal and enhances the abrasion ratio of PDC. Furthermore, Gly effectively relieved internal stresses within PDC and formed interconnected pore structures between diamond particles. These changes reduced the risk of delamination and cracking caused by residual stresses, thereby enhancing the service reliability of the material.