Basic Mechanics of the Metal-Cutting Process

1944 ◽  
Vol 11 (3) ◽  
pp. A168-A175 ◽  
Author(s):  
M. Eugene Merchant
Keyword(s):  
High Speed ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Orthogonal Cutting ◽  
Cutting Edge ◽  
Cutting Process ◽  
Work Piece ◽  
Machining Operations ◽  
Work Done ◽  
Metal Work

Abstract The author presents a mathematical analysis of the geometry and mechanics of the metal-cutting process, covering two common types of geometry which occur in cutting. This analysis offers a key for the study of engineering problems in the field of metal cutting in terms of such fundamental quantities as strain, rate of shear, friction between chip and tool, shear strength of the metal, work done in shearing the metal and in overcoming friction, etc. The two cases covered are, in essence, that of a straight-edged cutting tool moving relative to the work-piece in a direction perpendicular to its cutting edge, termed “orthogonal cutting,” and that of a similar cutting tool so set that the cutting edge is oblique to the direction of relative motion of tool and work, termed “oblique cutting.” Equations are developed which permit the calculation of such quantities as those just enumerated from readily observable values. The theoretical findings are particularly applicable and significant in the case of present-day high-speed machining operations with sintered-carbide tools.

Cutting Force and Friction Modelling in High Speed End-Milling

2015 ◽  
Author(s):  
Sunday J. Ojolo ◽  
Olumuwiya Agunsoye ◽  
Oluwole Adesina ◽  
Gbeminiyi M. Sobamowo
Keyword(s):  
Temperature Field ◽  
Temperature Distribution ◽  
Cutting Forces ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Tool ◽  
End Milling ◽  
Cutting Process ◽  
Machining Process ◽  
Work Piece

Temperature field in metal cutting process is one of the most important phenomena in machining process. Temperature rise in machining directly or indirectly determines other cutting parameters such as tool life, tool wear, thermal deformation, surface quality and mechanics of chip formation. The variation in temperature of a cutting tool in end milling is more complicated than any other machining operation especially in high speed machining. It is therefore very important to investigate the temperature distribution on the cutting tool–work piece interface in end milling operation. The determination of the temperature field is carried out by the analysis of heat transfer in metal cutting zone. Most studies previously carried out on the temperature distribution model analysis were based on analytical model and with the used of conventional machining that is continuous cutting in nature. The limitations discovered in the models and validated experiments include the oversimplified assumptions which affect the accuracy of the models. In metal cutting process, thermo-mechanical coupling is required and to carry out any temperature field determination successfully, there is need to address the issue of various forces acting during cutting and the frictional effect on the tool-work piece interface. Most previous studies on the temperature field either neglected the effect of friction or assumed it to be constant. The friction model at the tool-work interface and tool-chip interface in metal cutting play a vital role in influencing the modelling process and the accuracy of predicted cutting forces, stress, and temperature distribution. In this work, mechanistic model was adopted to establish the cutting forces and also a new coefficient of friction was also established. This can be used to simulate the cutting process in order to enhance the machining quality especially surface finish and monitor the wear of tool.

An Integral Method to Determine Workpiece Flow Stress and Friction Characteristics in Metal Cutting

2015 ◽  
Vol 9 (6) ◽  
pp. 775-781
Author(s):  
Norfariza Wahab ◽  
◽  
Yumi Inatsugu ◽  
Satoshi Kubota ◽  
Soo-Young Kim ◽  
...  
Keyword(s):  
Flow Stress ◽  
Strain Rate ◽  
Cutting Forces ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Edge ◽  
Cutting Process ◽  
Machining Parameters ◽  
Friction Characteristics ◽  
High Speed Cutting

In recent times, numerical simulation techniques have been commonly used to estimate and predict machining parameters such as cutting forces, stresses, and temperature distribution. However, it is very difficult to estimate the flow stress of a workpiece and the friction characteristics at a tool/chip interface, particularly during a high-speed cutting process. The objective of this study is to improve the accuracy of the present method and simultaneously determine the characteristics of the flow stress of a workpiece and friction at the cutting edge under a high strain rate and temperature during the cutting process. In this study, the Johnson-Cook (JC) flow stress model is used as a function of strain, strain rate, and temperature. The friction characteristic was estimated by minimizing the difference between the predicted and measured results of principal force, thrust force, and shear angle. The shear friction equation was used to estimate the friction characteristics. Therefore, by comparing the measured values of the cutting forces with the predicted results from FEM simulations, an expression for workpiece flow stress and friction characteristics at the cutting edge during a high-speed cutting process was estimated.

The effect of coatings on the cutting process, friction, forces and predictive cutting models in machining operations

2002 ◽  
Vol 216 (3) ◽  
pp. 347-356 ◽  
Author(s):  
E J A Armarego ◽  
S Verezub ◽  
P Samaranayake
Keyword(s):  
High Speed ◽  
Thrust Force ◽  
Orthogonal Cutting ◽  
High Speed Steel ◽  
Cutting Process ◽  
Force Component ◽  
Friction Forces ◽  
Technological Performance ◽  
The Many ◽  
Machining Operations

The effects of the popular TiN and TiCN coatings on the cutting process, friction and predictive mechanics of cutting models for forces and power in machining operations are investigated. Extensive orthogonal cutting and turning tests on steel work materials have shown that the cutting process and predictive force models are not qualitatively affected by these coatings. Quantitatively, both coatings are equally effective in reducing the friction, forces and power in orthogonal cutting when applied to high-speed steel (HSS) tools and equally ineffective when applied to carbide tools. Both TiN and TiCN coatings applied to HSS tools resulted in modest reductions in the power force component and power of 12–30 per cent ‘on average’ with larger reductions in the thrust force component of about 50 per cent ‘on average’. Considerably more research seems necessary to understand better and to predict quantitatively the effects of the many coating-substrate combinations on the technological performance of machining operations, essential for optimizing the economic performance of these operations.

Computer Simulation of AISI D2 Orthogonal Cutting Using Finite Element Method

2012 ◽  
Vol 499 ◽  
pp. 39-44
Author(s):  
L. Yan ◽  
Feng Jiang ◽  
Y.M. Rong
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Cutting Tool ◽  
Orthogonal Cutting ◽  
Damage Model ◽  
Chip Morphology ◽  
Simulation Method ◽  
Cutting Process ◽  
Aisi D2 ◽  
Cutting Processes

This paper presented a finite element simulation model for the analysis of AISI D2 orthogonal cutting process using TiAlN coated inserts. Firstly, AISI D2 material constitutive model was built based on power law model, which was used in the FEM codes to describe the effect of strain, strain rate and temperature on the material flow stress. In modeling the chip formation, a damage model was employed to predict the chip separation. Then cutting edge radius and thickness of TiAlN coating of cutting tool were measured by SEM. Friction coefficients of cutting tool against AISI D2 steel were obtained by ball-on-plate friction tests on UMT-2 high speed tribometer. Finally, finite element simulations of AISI D2 orthogonal cutting processes were performed using AdvantedgeTM software. The simulated results of cutting forces and chip morphology showed good agreement with the experimental results, which validated the reliability of the cutting process simulation method.

Machining Characteristics of Leaded Steel

1960 ◽  
Vol 82 (2) ◽  
pp. 347-359 ◽  
Author(s):  
Fenton L. Bagley ◽  
Roy Mennell
Keyword(s):  
Metal Cutting ◽  
Cutting Tool ◽  
Cutting Process ◽  
Work Piece ◽  
Two Dimensional ◽  
Life Data ◽  
Wide Range ◽  
Machining Characteristics ◽  
Lead Addition ◽  
Cutting Speeds

The effects of lead addition in alloy steel upon the metal-cutting process were explored over a wide range of conditions. In particular, a range of cutting speeds (from 50 to 800 fpm) and workpiece hardness (from 230 to 450 Bhn) were investigated on one work-piece material (4340) using principally a carbide (C-6) cutting tool. Orthogonal (two-dimensional) data was taken to describe the metal-cutting process, and tool-life data were obtained by running a typical production tool to failure at the various cutting conditions. Several mechanisms to explain experimental results, including lead acting as a lubricant, are discussed.

The Numerical Investigation of Stress Distribution on the Rake Face for Grooved Cutting Tool Inserts

2011 ◽  
Vol 223 ◽  
pp. 304-313
Author(s):  
E. Kwiatkowska ◽  
Piotr Niesłony ◽  
W. Grzesik
Keyword(s):  
Metal Cutting ◽  
Cutting Tool ◽  
Orthogonal Cutting ◽  
Cutting Tools ◽  
Cutting Process ◽  
Rake Face ◽  
Normal Stresses ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Chip Breakage

The development of an accurate model for the shear and normal stresses on the rake face is very important for modeling of the metal cutting mechanics. It is known that the stresses vary over the contact surfaces of the tool and change substantially with their configurations. On the other hand, the recent attempts were generally addressed to orthogonal cutting process and tools with flat rake faces. At present, grooved tools with complex rake faces are commonly applied in the industry. In this study a plane strain finite element (FEM) program AdvantEdge was used to simulate the cutting process with some disposable grooved cutting tools. Both the reduced von Mises stresses and their components in x and y directions were considered and visualized for appropriate chip formation stages. In particular, the distribution of the contact stresses was revealed when chip breakage occurs. The simulated results were correlated with the geometry of the chip breaker and process parameters.

Finite Element Analysis of High Speed Cutting Tool

2012 ◽  
Vol 268-270 ◽  
pp. 496-499 ◽  
Author(s):  
Wei Fan ◽  
Xin Liu
Keyword(s):  
Finite Element ◽  
High Speed ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Cutting Process ◽  
Machining Process ◽  
Tool Geometry ◽  
High Speed Machining ◽  
High Speed Cutting ◽  
Finite Element Software

The cutting principle of high speed machining is analyzed, and the key technology of building high speed cutting finite element simulation model is systemic explained. By simplifying high speed cutting process, using the fastest solution of nonlinear finite element software ADINA which is development in recent years to establish the three dimensional finite element model of high speed metal cutting, and to predict the cutting force of different cutting tool geometry parameter combination of high speed cutting process, the high speed cutting processing cutting tool analysis and processing parameter optimization analysis method are put forwarded, so as to provide a new tool for the research of high speed machining process and provide basis for the cutting tool choice during high-speed nc cutting process.

Methodology for the Measurement of the Heat Partitioning by Thermal Imaging in the Orthogonal Cutting Process

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
T. Augspurger ◽  
T. Bergs ◽  
B. Döbbeler ◽  
A. Lima
Keyword(s):  
Process Parameters ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Thermal Conditions ◽  
Heat Fluxes ◽  
Cutting Process ◽  
Major Influence ◽  
Work Piece ◽  
Essential Question ◽  
Secondary Shear Zone

The thermal conditions like temperature distribution and heat fluxes during metal cutting have a major influence on the machinability, the tool life time, and the metallurgical structure of the work piece material. Though numerous analytical and experimental efforts have been developed in order to understand the thermal conditions in metal cutting, many questions still prevail. So, the exact form, distribution, and intensity of heat sources in the primary and secondary shear zone, which may describe the observed temperature distributions, are not explored to a satisfactory extend. On the other hand, the influence of the material properties like friction coefficient, heat conductivity, and shear strength is not yet fully understood. Another essential question is the heat flux partition among chip, work piece, and tool depending on process parameters and material. The particular novelty of the current investigation is a new methodological approach using modern thermal measurement system and postprocessing methods in order not only to measure the entire temperature field in the orthogonal cutting zone but also to calculate the affiliated heat flow distribution in the cutting process. Thus, the cutting process is treated as energy conversation process of the governing mechanical power into sensible heat. This point of view offers compatibility across process parameters and materials, thus new possibilities for process design.

scholarly journals Predicting Cutting Force and Primary Shear Behavior in Micro-Textured Tools Assisted Machining of AISI 630: Numerical Modeling and Taguchi Analysis

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 91
Author(s):  
Shafahat Ali ◽  
Said Abdallah ◽  
Salman Pervaiz
Keyword(s):  
Tool Life ◽  
High Performance ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Orthogonal Cutting ◽  
Cutting Tools ◽  
Cutting Temperature ◽  
Cutting Process ◽  
Cutting Fluids ◽  
Machining Performance

The cutting tool heats up during the cutting of high-performance super alloys and it negatively affects the life of the cutting tool. Improved tool life can enhance both the machinability and sustainability of the cutting process. To improve the tool life preferably cutting fluids are utilized. However, the majority of cutting fluids are non-biodegradable in nature and pose harmful threats to the environment. It has been established in the metal cutting literature that introducing microgrooves at the cutting tool rake face can significantly reduce the coefficient of friction (COF). Reduction in the COF promotes anti-adhesive behavior that improves the tool life. The current study numerically investigates the orthogonal cutting process of AISI 630 Stainless Steel using different micro grooved cutting tools. Results of the numerical simulations point to the positive influence of micro grooves on tool life. The results of the main effects found that the cutting temperature was decreased by approximately 10% and 7% with rectangular and triangular micro grooved tools, respectively. Over machining performance indicated that rectangular micro groove tools provided comparatively better performance.

Finite Element Analysis of the Influence of the Material Constitutive Law Formulation on the Chip Formation Process During a High Speed Metal Cutting

2012 ◽  
Author(s):  
Adinel Gavrus ◽  
Pascal Caestecker ◽  
Eric Ragneau
Keyword(s):  
Finite Element ◽  
Formation Process ◽  
Chip Formation ◽  
High Speed ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Constitutive Law ◽  
Cutting Process ◽  
Contact Friction ◽  
Numerical Predictions

During the last decades, the importance of machining in manufacturing industry has required rigorous scientific studies concerning the chip formation process in order to determine optimal speeds, feeds or other technological parameters. For all types of machining including turning, milling, grinding, honing or lapping, the phenomenon of chip formation is similar in terms of the local interaction between the tool and the work piece. Because of the intensive use of CNC machine tools producing parts at ever-faster rates, it has become important to provide analysis of high speed cutting where complex loading conditions occur during the fabrication process: high gradients of the thermo-mechanical variables, strong nonlinearities of the thermo-mechanical coupling, large plastic strains, extremely high strain rates compared to that of other forming processes, important influence of the contact friction and of the microstructure evolution. Today many scientific researches are focalized on finite element analyses of the chip formation and of its morphology evolution during a high speed metals cutting process. To improve the quality of the numerical predictions, a better description of the local shear band formation is needed, using adequate rheological models. On this point of view this paper deals with the influence of the rheological behavior formulation on the morphology and geometry of the chip formation during a finite element simulation of a high speed metal cutting process. Numerical simulations of a high speed orthogonal cutting of special steels are employed to analysis the sensitivity of the numerical results describing the local cutting area with respect to different rheological laws: Norton-Hoff or Cowper-Symonds model, Johnson-Cook one or Zerilli-Armstrong formulation. To obtain a better description of the local material loadings and to take into account the important gradient of the strain rate, plastic strain and temperature values, a more adequate constitutive model is proposed by the author.

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