An insight into the origins of the cutting edge profile errors of the micro diamond tools: from a mechanical perspective

Micro diamond tools are critical for ultra-precision and micro machining within high-tech manufacturing industry, owing to their exceptional cutting performances. Nevertheless, attaining high cutting edge profile accuracy during mechanical lapping remains a formidable challenge, as anisotropic material removal and dynamic process forces frequently lead to cutting edge waviness exceeding 100 nm. This work delves into the formation mechanisms of these profile errors through comprehensive theoretical and experimental analyses. A mechanical model encompassing friction, abrasive scratching, cutting resistance and dynamic impacts during the lapping of micro diamond tools is established and validated via lapping experiments. By disclosing the relationship between lapping force distribution patterns and cutting edge profiles, the underlying causes of cutting edge profile errors are further uncovered. Subsequently, a practical methodology is proposed to improve the profile accuracy of micro rounded diamond tools. The results indicate that lapping force anisotropy is directly associated with cutting edge waviness, while high-frequency impacts facilitate the homogenization of material removal. This work provides a mechanistic comprehension of edge waviness formation and presents practical strategies to improve the profile accuracy of micro diamond tools for precision machining applications, addressing a pivotal limitation in the fabrication of micro diamond tools.