Periodic Bond Chain Model for Estimation of the Anisotropy of Diamond Cutting Tools

Diamond cutting tools exhibit a strong anisotropy in mechanical lapping.Therefore,it is crucial to establish a proper model to quantitatively describe the anisotropy.After thoroughly analyzing the material removal mechanism in mechanical lapping of diamond cutting tools,a periodic bond chain(PBC) model was set up to quantitatively describe the anisotropy of tools' mechanical lapping based on the PBC theory.The spatial arrangements of the crystal planes in the typical simplexes of the diamond crystal were judged using this model,either their 'soft' and 'hard' directions.Then lapping experiments of two crystal planes {100} and {110} were executed on rounded diamond cutting tools lapping machine.The maximum plastic groove depths were 19.8 nm and 5.1 nm for lapping along the crystal directions 100 and 110 respectively on the crystal plane {100},and 9.8 nm and 3.5 nm on the crystal plane {110} respectively.These results complied with those predicted by the PBC model.Finally,the combination of crystal planes was optimized with the proposed model and according to the tools wearing condition in use,in which crystal plane {110} was applied to both the rake face and the flank face.The PBC model will give a strong support for the mechanical lapping of diamond cutting tools.