Effect Of Tool Rake Angle Research Articles

Study on the atomic removal behavior and damage formation mechanism of nano cutting copper–nickel alloy with diamond tool

The effects of tool rake angle and cutting depth on cutting temperature, cutting force, friction coefficient of rake tool face, atomic accumulation of chip flow and removal, surface quality, sub-surface damage layer thickness, atomic stress, and dislocation evolution were studied by molecular dynamics simulations. The results showed that the cutting temperature was concentrated on the chip, and the chip was easy to flow out with the increase of the tool rake angle, which weakens the extrusion and shearing action of the workpiece, resulting in the gradual reduction of tangential force. The tool rake angle of 10° is beneficial to improve the surface/subsurface quality of the workpiece. The minimum root-mean-square roughness obtained was 0.73 Å. The atomic stress of the workpiece was mainly concentrated around the area of interaction with the tool, and the atoms on the finished surface underwent elastic recovery, so the atomic stress was not significant. The 1/6<112> (Shockley) dislocation density had always been in the leading position, and 1/6<112> (Shockley) dislocation was continuously synthesized and decomposed during the nano-cutting process. With the increase of cutting depth, the number of atoms removed increases rapidly, and the width of chip side flow increases, but the symmetry is weakened. The contour line map even shows deep wave valleys caused by the absence of atoms, which increases the surface roughness. Moreover, the area and depth of the atomic stress distribution in the subsurface layer increase, and the number of amorphous atoms and dislocation density increase.

Investigations into effect of tool rake angle on nanocutting process for Zr-based amorphous alloy by molecular dynamics simulation

The nano cutting process of Zr-based amorphous alloy was simulated by molecular dynamics simulation in this paper. Through the research on the changing rule of cutting force in nano cutting of Zr-based amorphous alloy, it is found that the cutting force increases continuously, and the cutting rate is large at the initial stage of nano cutting, which may be related to the shear deformation of the atomic clusters or atomic clusters in the shear transition zone. The effect of cutting tool rake angle on nano cutting process for Zr-based amorphous alloy was studied. The simulation results show that the cutting force decreases with the increase of the rake angle of the cutting tool, and the friction coefficient between the rake face and the chip also decreases slightly. With the increase of the rake angle of the cutting tool, the pushing effect of the tool on the Zr-based amorphous alloy chip and the overall bending of the chip are weakened, leading to the increase of the chip height. The number of high-temperature atoms in the Zr-based amorphous alloy workpiece also decreases with the increase of the tool rake angle, and the cutting temperature distribution on the workpiece diffuses to the interior of the workpiece with the tool fillet as the center.

Effects of tool angles and uncut chip thickness on consumption of plastic deformation energy during machining process

Research on the underlying mechanism that controls the chip deformation and energy consumption is a basis to instruct the cutting process planning and improve the machining efficiency. The metal cutting process can be treated as purposeful separation of workpiece material, and the stress state located at the tool tip has great effect on the fracture of material being removed. Through studying the relationship between the stress triaxiality and chip formation process, this paper aims to reveal the effects of tool rake angle, inclination angle and uncut chip thickness on chip deformation behavior and associated energy consumption during machining of 1045 steel based on finite element method (FEM). A two-dimensional FEM model for orthogonal cutting is developed to study the effect of tool rake angle and uncut chip thickness on chip deformation, while a three-dimensional FEM model for oblique cutting is developed to investigate the effect of tool inclination angle. The parameter of chip compression ratio (CCR) is adopted to assess the chip plastic deformation and energy consumption under varied machining conditions. The cutting force component calculated based on CCR is compared with the total cutting force to demonstrate the dominant role of chip plastic deformation in cutting energy consumption. The results indicate that larger rake angle and smaller inclination angle of cutting tools as well as larger uncut chip thickness lead to increase of stress triaxiality near the tool tip, which can reduce the material fracture strain and be beneficial for the separation of material being removed from the bulk workpiece. This paper will be attractive from both practical and fundamental perspectives devoted to instructing the optimization of cutting parameters to improve the processing efficiency and reduce the energy consumption.

Experimental and simulation study of material removal behavior in ultra-precision turning of magnesium aluminate spinel (MgAl2O4)

Ultra-precision turning is one of the effective process methods to machine magnesium aluminate spinel with high efficiency and low damage. The influences of turning parameters and material microstructure on material removal behavior in ultra-precision turning of magnesium aluminate spinel (MgAl2O4) were investigated through experiment and simulation. A finite element method (FEM) model was developed to understand the effect of tool rake angle, cutting depth and cutting speed on the machined surface. Simulation results were verified experimentally by micro-groove cutting test. A negative rake angle tool can improve the plasticity of spinel and increase the ductile-brittle transition depth. However, the compressive stress field generated by the negative rake face brings the risk of more serious damage. Reducing cutting depth can suppress cracks. Elevating the cutting speed within a certain range does not deteriorate the surface quality and can increase the material removal rate. The anisotropy of spinel grains at micro-scale is of a great influence on the material behavior, leading to a non-uniform surface topography. In order to obtain a high-quality machined surface, the undeformed chip thickness must be smaller than the ductile-brittle transition depth of the most brittle grain. Experimental and simulation results suggest an optimized combination of turning parameters for a smooth surface by ultra-precision turning to achieve low-damage ultra-precision turning of polycrystalline hard and brittle materials.

Effects of tool rake angle and workpiece surface roughness on nanocutting of cu investigated using Multiscale simulation

ABSTRACT The effects of tool rake angle and workpiece surface roughness on the cutting mechanism and mechanics of Cu are studied using quasi-continuum simulations. These effects are investigated in terms of atomic trajectories, stress distribution, cutting force, resistance factor, and cutting ratio. The simulation results show that negative rake angles lead to a larger cutting force, lower resistance coefficient, and higher cutting ratio than those obtained with positive rake angles. For tools with an initial rake angle of 2° to 8°, the rake angle becomes negative during the cutting process due to the strong adhesion interaction between the tool rake face and chips. The resistance coefficient decreases with increasing tool rake angle for rake angles in the range of 2° to 8°. Tools with negative rake angles of −2° to −8° have similar cutting ratios. The cutting ratio decreases and cutting force increases with increasing surface roughness of the workpiece.

Effect of tool rake angle on the material removal mechanism transition of single-crystal silicon: a molecular dynamics study

Effect of tool rake angle on the material removal mechanism transition of single-crystal silicon: a molecular dynamics study

Effect of Tool Rake Angle and Crystal Orientation on Ductile Mode Cutting of Hard/Brittle Materials

The effects of negative rake angles on the ductile mode cutting of soda glass and sapphire were studied. In addition, the machining mechanism was studied using a groove-cutting model based on the orthogonal cutting theory. It was found that the specific cutting forces in ductile mode cutting increase on both the soda glass specimen and on the sapphire specimen when the rake angle of the tool becomes negative. The difference between the experimental data and theoretical data of the specific cutting forces becomes large when the tool has a high rake angle on the negative side. This is attributed to effects of the roundness of the edge, the effects of the roundness of the nose, and the plowing mechanism, which causes plastic flow of the work material to both sides of the groove. The specific cutting force of sapphire depends on the cutting direction against the crystal orientation. The specific cutting force of sapphire depends on the cutting direction in terms of the crystal orientation. The anisotropy of the cutting force of sapphire also depends on the rake angle of the tool.

Damage mechanisms of polycrystalline aluminate magnesium spinel (PAMS) under different loading conditions of indentation and micro-cutting tests

This paper studies the damage mechanisms of polycrystalline aluminate magnesium (PAMS) under different loading conditions of indentation tests and micro-cutting with various rake angles of the cutting tools. A decreasing trend is confirmed in the hardness values with growing loadings. The observed hardness value approaches a plateau at about 1406–1679 HV. The tardive cracks, which break out spontaneously within a delayed period of time following the end of indentation, are for the first time observed in the indentation experiment of this paper. The tardive crack originates from a crack system containing a lateral subsurface crack with two median cracks on its both sides. These results imply that PAMS can store the unbalanced strain energy induced by the applied loading within the vicinity of the loaded volume which will be released in accordance with the intergranular crack-growing path extending to the surface. In addition, the linear plunge-cutting tests coin the effect of tool rake angle: the tool with a zero rake angle produces poor surface quality with sever surface damages whilst the tools with negative rake angles can improve the ductility of PAMS to a certain extent. However, negative rake angles are proved to be the root cause of median cracks and large spalling fractures. On the contrary, a positive rake angle tool can be applied to reduce the severity of surface damage and confine the damage patterns mainly as small spallings fractures. Besides the experimental study, finite element method (FEM) models are developed to reveal the underlying mechanism of the rake-angle effect on the micro-cutting process. The simulation results visualise the different stress distributions in the uncut areas and prove that a tool with positive rake angle can transfer the stress to the uncut chip layer whereby the damage probability to the machined surface is significantly reduced.

Modeling and simulation on the effect of tool rake angle in diamond turning of KDP crystal

In this work, to investigate the effect of tool rake angle in diamond turning of KDP crystal, a novel theoretical model that considers the material properties, tool geometries, cutting parameters and the suppression of hydrostatic pressure is established by formulating the relative length of crack (RLC). Subsequently, interrupted-cutting experiments with different tool rake angles are performed, and an effective method for crack evaluation is used to acquire the experimental results of RLC. Moreover, using the inverse analysis for material model parameters by nanoindentation test and dimensional analysis method, a novel 3D hybrid model with the use of smoothed particle hydrodynamics and finite element method is constructed to simulate the diamond turning process of KDP crystal. As expected, the dynamic distribution of hydrostatic pressure ahead of the active cutting edge is successively investigated to reveal the underlying mechanism of tool rake angle, which is a significant factor that affects crack propagation, surface generation and chip formation. The results show that the developed theoretical model which considers the suppression of hydrostatic pressure has a satisfactory accuracy in predicting the quantitative relationship between tool rake angle and crack propagation. Large negative rake angles from −25° to −45° are suggested for the diamond turning process of KDP crystal.

Finite element analysis of the effect of tool rake angle on brittle-to-ductile transition in diamond cutting of silicon

Brittle-to-ductile transition plays a crucial role in ultra-precision machining of hard-brittle materials. In the present work, we investigate the brittle-to-ductile transition in diamond grooving of monocrystalline silicon by finite element modeling and simulation based on Drucker-Prager constitutive model. The brittle-to-ductile transition behavior is distinguished by analyzing evolutions of chip profile and cutting force. Corresponding diamond grooving experiment using the same machining configuration with the finite element simulation is also carried out to derive the critical depth of cut for the brittle-to-ductile transition. The comparison of experimental value of the critical depth of cut and predicted one by the finite element simulation demonstrates the high accuracy of as-established finite element model. Subsequent finite element simulations are performed to investigate the influence of rake angle of cutting tool on both diamond grooving and conventional diamond cutting with a constant depth of cut, which demonstrates a prominent dependence of brittle-to-ductile transition of silicon on the rake angle ranging from − 60° to 0°. And a critical rake angle for the most pronounced ductile machinability of silicon is found.

Effects of tool rake angle and tool nose radius on surface quality of ultraprecision diamond-turned porous silicon

This paper presents an investigation of the effects of tool rake angle and nose radius on the surface quality of ultraprecision diamond-turned porous silicon. The results showed that as rake angle decreases, the high-stress field induced by the tool edge increases, causing microcracks to propagate extensively near the pore walls. As a result, the ductile-machined areas shrank under a negative tool rake angle. On the other hand, brittle fracture occurred around pores released cutting pressure significantly. These trends of rake angle effects are distinctly different from those in the cutting of non-porous silicon. Finite element simulation of stress in the cutting area agreed with the experimental results. The results also indicated that using a tool with a bigger nose radius suppressed brittle fractures around the pore edge and improved surface quality. Raman spectroscopy of the ductile-machined surfaces revealed that the amorphization of the subsurface layer became more significant when decreasing tool rake angle or increasing tool nose radius. By choosing the optimal tool geometry, a high quality surface can be achieved on porous silicon, which demonstrates the capability of the diamond turning process to fabricate high-precision components.

Effect of tool rake angle on cutting mechanism for nano-machining of hard-brittle material

Effect of tool rake angle on cutting mechanism for nano-machining of hard-brittle material

Investigation of influence of tool rake angle in single point diamond turning of silicon

This paper presents an investigation of the effect of tool rake angle in single point diamond turning (SPDT) of silicon using experimental and simulation methods. Machining trials under the same cutting conditions were carried out using three different rake angle tools. In order to delve further into the rake angle effect on the output parameters including material removal, stresses and crack formation, at the onset of chip formation and steady-state conditions, a simulation study using smoothed particle hydrodynamics (SPH) approach was performed. The simulation results were incorporated and found in good agreement with experimental observations. The results indicate that diamond tool wear rate and surface generation mechanism significantly vary using different rake angle tools. The continuance of compressive and shear deformation sequence at the chip incipient stage governs the high-pressure phase transformation (HPPT) as a function of rake angle and tool wear. The capability of diamond tool to maintain this sequence and required hydrostatic pressure under worn conditions is highly influenced by a change in rake angle. The proportional relationship of cutting force magnitude and tool wear also differs owing to disparate wear pattern which influence distribution of stresses and uniform hydrostatic pressure under the tool cutting edge. This subsequently influences structural phase transformation and therefore frictional resistance to cutting. Mainly frictional groove wear was found dominant for all diamond tools in machining of silicon.

Low-temperature machining in a fully submerged cryogenic environment

ABSTRACTThe role of an immersive cryogenic environment in affecting material response in machining was explored using dynamometry, calorimetry, electron microscopy, and microindentation. Effects of tool rake angle on energy dissipation, stored energy of cold work, deformed microstructure, and hardening were evaluated for machining under a fully submerged cryogenic cutting environment and a dry cutting environment. Sustained immersion of the cutting zone in liquid nitrogen resulted in greater energy dissipation and hardening in the work and machined subsurface. This increased hardening at low temperature was directly linked to greater microstructure refinement and a lower fraction of dissipated energy stored in the form of added defects and grain boundaries. Various microstructure types with domain sizes from microscale to nanoscale were developed in the machined chips, depending on the rake angle and temperature used.

Simulation Analysis of the Effects of Tool Rake Angle for Workpiece Temperature in Single Crystal Copper Nanometric Cutting Process

Simulation Analysis of the Effects of Tool Rake Angle for Workpiece Temperature in Single Crystal Copper Nanometric Cutting Process

Finite Element Modeling of the Effect of Tool Rake Angle on Cutting Force and Tool Temperature during High Speed Machining of AISI 1045 Steel

A finite element model (FEM) of an orthogonal metal-cutting process is used to study the influence of tool rake angle on the cutting force and tool temperature. The model involves Johnson-Cook material model and Coulomb’s friction law. A tool rake angle ranging from 0° to 20° and a cutting speed ranging from 300 to 600 m/min were considered in this simulation. The results of this simulation work are consistent optimum tool rake angle for high speed machining (HSM) of AISI 1045 medium carbon steel. It was observed that there was a suitable rake angle between 10° and 18° for cutting speeds of 300 and 433 m/min where cutting force and temperature were lowest. However, there was not optimum rake angle for cutting speeds of 550 and 600 m/min. This paper can contribute in optimization of cutting tool for metal cutting process.

Finite Element Modelling of the effect of tool rake angle on tool temperature and cutting force during high speed machining of AISI 4340 steel

In this paper, a Finite Element Method (FEM) based on the ABAQUS explicit software which involves Johnson-Cook material model was used to simulate cutting force and tool temperature during high speed machining (HSM) of AISI 4340 steel. In this simulation work, a tool rake angle ranging from 0° to 20° and a range of cutting speeds between 300 to 550 m/min was investigated. The purpose of this simulation analysis was to find optimum tool rake angle where cutting force is smallest as well as tool temperature is lowest during high speed machining. It was found that cutting forces to have a decreasing trend as rake angle increased to positive direction. The optimum rake angle observed between 10° and 18° due to decrease of cutting force as 20% for all simulated cutting speeds. In addition, increasing cutting tool rake angle over its optimum value had negative influence on tool's performance and led to an increase in cutting temperature. The results give a better understanding and recognition of the cutting tool design for high speed machining processes.

Effect of Cutting Parameters on Cutting Temperature of TiAl6V4 Alloy

A Finite Element Modeling (FEM) and Simulation was Used to Investigate the Effect of Tool Rake Angle, Cutting Speed and Feed Rate on the Cutting Temperature of Tial6v4 Alloy. the Purpose of this Study was to Find Proper Cutting Parameters for Machining of Titanium Alloy where Cutting Temperature was Lowest. A FEM Based on ABAQUS Software which Involves Jonson-Cook Material Model and Coulomb’s Friction Law was Applied to Simulate an Orthogonal Cutting Process. in this Simulation Work, a Range of Tool Rake Angle from 0° to 10°, a Range of Cutting Speed from 300 m/min to 600 m/min and a Range of Feed Rate between 0.1 Rev/mm and 0.25 Rev/mm were Investigated. the Simulation Results Indicated that Increase in Rake Angle Reduces Cutting Temperature while Increasing Cutting Speed and Feed Rate Increase the Cutting Temperature.

Effects of Tool Rake Angle on the Curved Radius during Planing-Forming Process of Fine Heat Sink

Planing-forming is a new process to machine fin heat sinks. This paper investigates the effects of the tool rake angle on the curved radius during planing-forming process by 2-D coupled thermo-mechanical finite element method and experiment verification. With the increasing of the tool rake angle from 0° to 30°, the curved radius increased. When the tool rake increased form 30°to 60°, the curved radius turned stable. After the chip displaced from the tool rake, the fin’s curling up due to the distribution gradient of the residual strain.

Effects of tool edge radius and rake angle on ductile machining process of CaF&lt;SUB align=right&gt;2

The submicron level orthogonal cutting process of CaF 2 has been investigated by the finite element approach, and the effects of tool edge radius on cutting force, cutting stress and chip formation were investigated. T results indicate that increasing the tool edge radius causes a significant increase in thrust force and a decrease in chip thickness. A hydrostatic pressure (~2 GPa) is generated in the cutting region. The volume of the material under high pressure increases with the edge radius. The effects of tool rake angle on cutting stress and chip formation were also investigated. The results indicate that increasing the tool rake angle causes a significant increase in stress and a decrease in chip thickness. The simulation results from the present study show the optimal tool rake angle to the ultra-precision cutting of CaF 2 is –20°. The simulation results from the present study can be applied for optimising tool geometry design in CaF 2 machining.