Investigate the initialization of materials removal and deformation in single point diamond fly cutting technique using multiscale method

Diamond fly cutting (DFC) is a technique which can accurately and efficiently generate shapes in the micro & nanometer scale. However, the miniaturization of parts and the small depth of cut make the materials removal or deformation in the DFC different from the common machining technology. It is difficult to investigate materials deformation or failure by means of pure macroscopic or microscopic scale method. Multiscale method can study material behavior across different length & temporal scale simultaneously which is helpful about uncover important properties and materials response in DFC and thus being employed in this work. The results show that several slipping-dislocation systems are generated with feeding of the cutting tool while most of them extend along the rake angle of cutting tool. The plastic deformation is a discrete process in the atomic scale while it is generally considered as continuum process in the macroscopic scale. The first slipping-band becomes the boundary of the following slipping process which leads to the different generation mechanism of the following dislocation. The dislocation density, cross-slip and junction increase with the increasing of strain rate. The dislocation density is gradually decreased far away from materials surface which justifies that most of the dislocation ought to be generated by the surface defects than by the internal defects. The dislocation can also be regenerated by the complicated dynamic behavior of the existing dislocations without external loading which lead to the complexity of the deformation process. The slipping-band can be considered as the green-channel of stress relaxation as the maximum stress is originated at the tool-workpiece contact area and gradually decreased in the further area. (C) 2018 Author(s).