A novel metal bond diamond tool electrodes based on boron-doped diamond grit for electrochemical discharge-assisted grinding of SiCf/SiC

Silicon carbide fiber reinforced silicon carbide matrix composites (SiC f /SiC) have been recognized as highly promising materials for advanced high-temperature applications in the aerospace industry. In the machining of SiC f/ SiC, electrochemical discharge-assisted grinding (ECD-G) method shows great potential for achieving high-efficiency, high-quality machining performance. However, undoped diamond grit (UDD) used in conventional diamond tool electrodes for ECD-G still suffers from poor electrical conductivity and inadequate self-sharpening ability, resulting in low material removal efficiency and poor surface quality of SiC f /SiC. To tackle this issue, we propose a novel Cu-bond diamond tool electrode based on boron-doped diamond (BDD), which exhibits much higher electrical conductivity and superior self-sharpening ability. Its enhanced conductivity, combined with the intrinsic discharge effect of BDD, synergistically improved the uniformity of electrochemical discharge (ECD) behavior. This facilitates more sufficient softening of SiC f /SiC, while also promoting the fracture of brittle BDD to generate numerous micro-cutting edges. Through the above design, the BDD micro-cutting edges can simultaneously improve machining efficiency and surface quality when processing these softened regions of SiC f /SiC. The results indicate that the machining efficiency of the BDD/Cu tool electrode increased by 21.8%, while the surface roughness of SiC f /SiC decreased by 21.2% compared with the conventional UDD/Cu tool electrode.