Polycrystalline diamond compact (PDC) is a widely used superhard material, and its thermal stability and wear resistance are the main factors determining its performance. The residual cobalt binder content in polycrystalline diamond (PCD) has a significant impact on the thermal stability and wear resistance of PDC. Therefore, cobalt removal treatment is required to improve the performance of PDC. The current cobalt removal methods mainly include acid leaching and electrolysis. This study proposes a novel coupling method that combines acid leaching and electrolysis for cobalt removal. Cobalt removal was conducted for 10 h under the conditions of electrolytic voltage of 12 V, direct current power supply current of 0.01 A, and sulfuric acid electrolyte concentration of 9.2 mol/L. The cobalt removal effect was evaluated using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The hardness and elastic modulus of PDC before and after cobalt removal were measured using nanoindentation experiments. The results indicate that the coupled electrolysis process effectively removes the cobalt phase in the PCD layer while retaining the WC phase. The hardness and elastic modulus of PDC decrease after the removal of cobalt binder, and the cobalt removal depth can reach 807 μm.

中文翻译：

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酸浸与电解耦合机理中多晶金刚石复合片脱钴评价


聚晶金刚石复合片（PDC）是一种应用广泛的超硬材料，其热稳定性和耐磨性是决定其性能的主要因素。聚晶金刚石（PCD）中残留的钴结合剂含量对PDC的热稳定性和耐磨性有显着影响。因此需要进行脱钴处理来提高PDC的性能。目前除钴方法主要有酸浸法和电解法。本研究提出了一种结合酸浸和电解去除钴的新型耦合方法。电解电压12V、直流电源电流0.01A、硫酸电解液浓度9.2mol/L条件下脱钴10h。使用扫描电子显微镜（SEM）、能量色散光谱（EDS）和X射线衍射（XRD）评估钴去除效果。采用纳米压痕实验测量除钴前后PDC的硬度和弹性模量。结果表明，耦合电解过程有效去除了PCD层中的钴相，同时保留了WC相。去除钴粘结剂后PDC的硬度和弹性模量下降，钴去除深度可达807μm。