Increase Of Cutting Edge Radius Research Articles

Numerical Modeling of the Effect of Cutting-Edge Radius on Cutting Force and Stress Concentration during Machining.

Cutting is the primary method of material removal, and the quality of machined parts depends on the geometry of cutting tools. In this paper, a new cutting force coefficient model is established, revealing the influence of cutting-edge radius on the cutting process. The effects of cutting-edge radius on the shear angle and cutting force components are analyzed by finite element simulations. A series of simulations is conducted, and the results show that with increased cutting-edge radius, the shear angle decreases nonlinearly, and the cutting force increases gradually. Additionally, the growth rate of the feed force caused by increasing the cutting-edge radius is higher than that of the tangential force. Furthermore, the stress concentration area of the machined surface extends from the surface to the subsurface as the cutting-edge radius increases. The results of this research show that changing the cutting edge affects the cutting force component, shear angle, and stress concentration range during the cutting process. These results provide a theoretical reference for predicting the residual stress in parts.

Effect of tool edge radius on material removal mechanism in atomic and close-to-atomic scale cutting

For mechanical cutting, when cutting depth is decreased to atomic and close-to-atomic scale(ACS), the material removal mechanism would be dominated by dislocation motion, different from conventional cutting and nanocutting. It is is greatly influenced by cutting edge radius effect in the aspects of chip formation, cutting forces, and stress distribution, etc. There appear three deformation zones in ACS cutting, including dislocation slip zone, chip formation zone and elastic deformation zone. As cutting-edge radius increases, both of dislocation slip zone and chip formation zone are suppressed while the elastic deformation zone tends to continually grow. When cutting edge radius is increased to be larger than a threshold, the elastic deformation zone is further transformed into one elastic and plastic deformation zone, while a very small chip formation zone, and dislocation zone is remained ahead of rounded cutting edge. Consequently, though the minimum cutting depth is decreased to single atomic layer, the material removal behaviour is also dominated by extrusion action of cutting tool, following the mechanism of nanocutting. The research findings would provide theoretical guidelines to the cutting tool design for atomic and close-to-atomic scale cutting.

Finite Element Simulation of the Cutting Process for Inconel 718 Alloy Using a New Material Constitutive Model

Inconel 718 alloy is a typical difficult-to-cut material and widely used in the aerospace industry. Finite element simulation is an efficient method to investigate the cutting process, whereby a work material constitutive model plays an important role. In this paper, finite element simulation of the cutting process for Inconel 718 alloy using a new material constitutive model for high strain rates is presented. The effect of tool cutting edge radius on the cutting forces and temperature is then investigated with a view to facilitate cutting tool design. It is found that as the cutting edge radius increases, the characteristics of tool-work friction and the material removal mechanisms change, resulting in variation in cutting forces and temperature. It is shown that a smaller cutting edge radius is preferred to reduce the cutting forces and cutting temperature.

Design of a computer aided quick-stop device for study of dead metal zone formation

The use of quick-stop device allows observing a sequence of frozen images focused on the chip formation area when machining in orthogonal turning tests. This work records the development of a quick-stop device employing a servo motor. The present invention relates generally to a quick stop device, for combination with a cutting machine that is able to abruptly interrupt the cutting process between a cutting tool and the surface being cut. A dead metal zone is clearly seen when using rounded-edge cutting tools. In this study, variation of the dead metal zone is examined with the computer aided quick-stop device (CAQSD). It is clear from the experimental photomicrographs that as the cutting edge radius increases, dead metal zone increases.

Finite Element Analysis of the Influence of Cutting Edge Radius on Mechanical-Thermal Distribution in High-Speed Cutting TiAl6v4

On the basis of analyzing the cutting edge structure and cutting edge radius measurement of high-speed insert, thermal - mechanical coupling finite element method (FEM) is used in this paper, to obtain the effect law of different cutting edge radius on the mechanical-thermal distribution of high-speed cutting TiAl6V4. At last, cutting experiments are carried out to verify FEM results. There is a clear exposition of the intrinsic reason why the cutting edge radius has influence on the mechanical -thermal distribution of high-speed cutting process. The results indicate that the experimental results have a good agreement with FEM; with the cutting edge radius increases, cutting force increases; cutting temperature is not monotonic, but there exists an optimum edge radius that makes temperature lowest; cutting edge changes the plastic flow of materials around tool tip and broaden plastic deformation zone. The cutting edge radius has a greater impact on equivalent stress.

Study of the temperature and stress in nanoscale ductile mode cutting of silicon using molecular dynamics simulation

Abstract In nanoscale cutting of brittle materials, it has been found that there is a brittle–ductile transition when the cutting tool edge radius is reduced to nanoscale and the undeformed chip thickness is smaller than the tool edge radius. In order to understand the mechanism of the brittle–ductile transition, the cutting characteristics, such as stress and temperature in the cutting region, have to be investigated. However, since the machining size is very small, on the nanoscales, it's very difficult to measure the temperature and stress in the chip formation zone experimentally. In this study, the molecular dynamics (MD) method is employed to model and simulate the nanoscale ductile mode cutting of monocrystalline silicon wafer. The MD simulation results show that the temperature rise in the cutting zone will affect the diamond tool. In the cutting process, the thrust force is larger than the cutting force. As the tool cutting edge radius increases, the shear stress in the workpiece material around the cutting edge will decrease. When the shear stress is so low that it is insufficient to sustain dislocation emission in the chip formation zone, crack propagation becomes dominating. Consequently, the chip formation mode changes from ductile to brittle.

Effect of Rounded Cutting Edge Radius on Residual Stress within Machined Sublayer

A coupled thermal-mechanical model of plane-strain orthogonal metal cutting with continuous chip formation is developed to investigate the residual stresses in the finished workpiece. Deformation of the workpiece material is treated as elastic-viscoplastic with isotropic strain hardening, and the numerical solution accounts for coupling between plastic deformation and the temperature field, including treatment of temperature-dependent material properties. Automatic continuous remeshing and adaptive meshing technique are employed to achieve chip separation at the tool tip region and a satisfactory solution. The finite element model is well validated by comparing values of the predicted cutting forces and residual stresses with experimental results. Based on the established finite element model, the effect of rounded cutting edge radius on residual stress distribution is analyzed. The results show that altered cutting edge radius clearly produced significant changes in residual stresses. The maximum tensile residual stress and its penetration depth decrease as the cutting edge radius increases.

Study of the mechanism of nanoscale ductile mode cutting of silicon using molecular dynamics simulation

In cutting of brittle materials, it was observed that there is a brittle-ductile transition when two conditions are satisfied. One is that the undeformed chip thickness is smaller than the tool edge radius; the other is that the tool cutting edge radius should be small enough—on a nanoscale. However, the mechanism has not been clearly understood. In this study, the Molecular Dynamics method is employed to model and simulate the nanoscale ductile mode cutting of monocrystalline silicon wafer. From the simulated results, it is found that when the ductile cutting mode is achieved in the cutting process, the thrust force acting on the cutting tool is larger than the cutting force. As the undeformed chip thickness increases, the compressive stress in the cutting zone decreases, giving way to crack propagation in the chip formation zone. As the tool cutting edge radius increases, the shear stress in the workpiece material around the cutting edge decreases down to a lower level, at which the shear stress is insufficient to sustain dislocation emission in the chip formation zone, and crack propagation becomes dominating. Consequently, the chip formation mode changes from ductile to brittle.