An investigation of the chip separation criterion with different physical properties and different cutting parameters for the ultra-precision machining of NiP alloy

This study focuses on the simulation of unique ultra–precision orthogonal cutting behaviour of non–electrolytic NiP alloy with the large–deformation finite element method, and explores the factors affecting the workpiece characteristics during the cutting process. The non–electrolytic NiP alloy, attached to the surface of a material by electroplating, is a special material developed to improve the machinability of nickel for ultra–precision cutting. The application of the coupled thermo–elastic–plastic model to a new cutting material often lacks the flow stress function. To overcome this problem, the data from a mi–axial tension experiment were used in this study to regress the flow stress and obtain the stress function. The objective is to let the industry use finite element methods to conduct qualitative analysis of the materials even in the absence of material properties. This paper uses the orthogonal cutting finite element model to simulate the cutting behaviour under such cutting parameters as the cutting depth and cutting velocity, which affect the cutting behaviours of the material. This study also examines the progress of such physical properties as the equivalent strain, equivalent stress, hydrostatic stress and strain energy density during the damaging process of removing the chip formation from the material in the cutting process in order to compare the difference in the criterion of separation under different conditions.