Theoretical analysis and finite element simulation of Poisson burr in cutting ductile metals

In metal machining, due to the material around the cutting edge subjected to high pressure, the subsurface generates a plastic deformation layer. And near the edge of finished surface the plastic deformation layer acts as a Poisson burr. This paper proposes an analytical model to predict the sizes of Poisson burr based on Flamant and Boussinseq equations in the plastic deformation problem. Besides the mechanical loading, the thermal effects are also taken into account in this model and assumed as moving heat sources during the cutting. The finite element simulation of aluminum 6061 alloy is utilized to verify the results of theoretical analysis. The results show that the sizes of Poisson burr has a great sensitivity to material properties and processing parameters. In addition, due to the serrated chips and brittle fracture of high strain rate, the Poisson burrs are not continuous along the longitudinal cutting direction. Through comparative study it is found that the theoretical model describes burr sizes with considerable accuracy. As a result, this paper may provide a better understanding the mechanism of Poisson burr formation and the theoretical basis of processing parameters optimization.