Study Of Chip Up-Curl Radius In Precision Matal Cutting Process

Studying the deformation process of metal cutting is an important issue on the metal cutting basic theory. Studying the chip geometry shape has great significance, which can illustrate the processing of the metal cutting and show the mechanism of chip deformation.First, based on N.Fang's study, by using slip-line theory, considering the influence of tool radius and the pre-deformation of chip, an orthogonal slip-line cutting model which reflecting chip up-curl radius is established in this paper. The velocity vector of slip-line field is set up at the same time.Second, considering the influence of strain and strain ratio in cutting process, slip-line angles and the expression of chip up-curl radius are deduced. Adopting single factor analysis method, the chip up-curl radius is calculated, and the chip up-curl radius'change with cutting velocity and the cutting tool's geometry shape is studied by Matlab software.Third, on the basis of mesh refinement and remesh technology as well as the consideration of chip's separation standard, the finite element simulation orthogonal model of metal cutting is set up by Deform-2D software. The simulation of chip deformation is carried out, then the chip up-curl radius'change law with cutting velocity and the cutting tool's geometry shape is studied. The comparison result with the calculation of slip line theory is given.Fourth, using of Deform-2D software, the effective-stress analysis on the chip is conducted, at the same time, velocity direction of each point on the chip is simulated. Considering the reality separating between chip and work-piece in metal cutting, a non-orthogonal cutting model is set up and the formation of chip in the course of non-orthogonal metal cutting is simulated by Deform-3D. Summarizing the above three aspects, the chip curling mechanism is analyzed and discussed.