Chip removal interference control in nano grooving for ultraprecision grating

Grating with nanogrooves is the key positioning sensor in ultraprecision machine tool equipment. The shape accuracy and surface quality of the nanogroove directly affect its optical performance and positioning accuracy. In non-free cutting of nanogrooves, the inherent chip removal interference is a serious problem for the machining quality. The innovation of this paper lies in the proposal of the formation mechanisms and suppression method of machining defects in nano grooving. The formation mechanisms of the groove bending deformation and the surface fracture striations in nano grooving on nickel phosphorus (Ni-P) are elucidated. Then, the model of suppressing the chip removal interference by optimizing the tool nominal working rake angle (TNWRA) is introduced, which is verified by the finite element method (FEM) simulations and ultraprecision cutting experiments on Ni-P. The groove bending deformation and surface fracture striations are revealed for the first time. The machining defects are suppressed by regulating the chip removal interference in nano grooving. By nano grooving under a TNWRA of +5°, high-quality and large-area nanogrooves on Ni-P are obtained.