New Developments in the Theory of the Metal-Cutting Process: Part I. The Ploughing Process in Metal Cutting

1960 ◽  
Vol 82 (4) ◽  
pp. 348-357 ◽  
Author(s):  
P. Albrecht
Keyword(s):  
Coefficient Of Friction ◽  
Metal Cutting ◽  
Rake Angle ◽  
Cutting Edge ◽  
Cutting Process ◽  
Force Diagram ◽  
The Coefficient Of Friction ◽  
Cutting Velocity ◽  
Real Value ◽  
Force Components

Revelation of the significance of “ploughing” in the metal-cutting process, which occurs because of the finite sharpness of the cutting edge, leads to a better understanding of the mechanics of the metal-cutting process. The concept of the ploughing force on the extreme cutting edge allows the development of a more complete force diagram which separates the ploughing force from the chip-tool interface force. Components of this more detailed force diagram have been verified experimentally. In terms of the new force diagram the real value of the coefficient of friction on the chip-tool interface has been found and the paradox of variation of the coefficient of friction with variation of rake angle explained. The paper also contributes to a better understanding of such events as the effect of cutting velocity upon tool forces, built-up edge, chip curling, and residual stresses in the work surfaces.

Deformation Characteristics of Ultra-Fine Grained Al6061 Chip in Machining by Finite Element Method

2010 ◽  
Vol 44-47 ◽  
pp. 2931-2934
Author(s):  
Chun Ling Wu ◽  
Bang Yan Ye
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Coefficient Of Friction ◽  
Metal Cutting ◽  
High Hardness ◽  
Rake Angle ◽  
Fine Grained ◽  
The Coefficient Of Friction ◽  
Cutting Velocity ◽  
Element Method

Ultra-fine grained chips with higher hardness and strength than bulk can be produced by severe plastic deformation during orthogonal metal cutting. A finite element method was developed to characterize the distribution of stress, strain, strain rate and temperature in the deformation area at different rake angles and cutting velocities. The coefficient of friction in the tool-chip interface is approximately obtained according model of mean coefficient of friction which is based on experiments in any machining conditions. The formation mechanics of ultra-fine grained chip is discussed and effect of rake angle on microstructure of chips is highlighted. The results of experiment and modeling have shown that chip materials with ultra-fine grained and high hardness can be produced with more negative tool rake angle at some lower cutting velocity.

Measuring fracture toughness from machining tests

2009 ◽  
Vol 223 (12) ◽  
pp. 2861-2869 ◽  
Author(s):  
Y Patel ◽  
B R K Blackman ◽  
J G Williams
Keyword(s):  
Fracture Toughness ◽  
Aluminium Alloy ◽  
Coefficient Of Friction ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Shear Plane ◽  
Rake Angle ◽  
Sufficient Information ◽  
The Coefficient Of Friction ◽  
Adhesion Toughness

An analysis of the forces involved in orthogonal cutting or machining is presented in which yielding on a shear plane is assumed. The fracture toughness Gc is included and it is observed that Gc may be determined by measuring the cutting and transverse forces together with the chip thickness for a range of cutting depths. This latter measurement enabled the shear plane angle ϕ to be determined experimentally. A simplified version of the analysis is also given in which ϕ is predicted by a cutting force minimization scheme. Neither scheme requires any details of the friction condition to be known since the transverse force is sufficient information for any type to be included in the analysis. A friction model including a coefficient of friction and an adhesion toughness is also utilized. Data for both polymer and metal cutting are taken from the literature and Gc is determined. In some datasets the tool rake angle α is also varied and the values of Gc and the yield stress σY are found to be independent of α. The force minimization method gives a good estimate of ϕ for most polymers. For metals (aluminium alloy, steel, and brass) the method worked well. For aluminium alloy Gc was independent of α and the predicted and measured ϕ values agreed. For steel and brass this was not so. Gc was mostly independent of α except at low values where high values of Gc were observed. A constant value of the coefficient of friction was observed for each α value but values for both the coefficient of friction and the adhesion toughness varied significantly with increasing rake angle.

Electrical Current at Metal Cutting Process: A Literature Review

2015 ◽  
Vol 808 ◽  
pp. 40-47 ◽  
Author(s):  
Raluca Daicu ◽  
Gheorghe Oancea
Keyword(s):  
Literature Review ◽  
Cutting Forces ◽  
Metal Cutting ◽  
Electrical Current ◽  
Cutting Edge ◽  
Cutting Process ◽  
Metallic Materials ◽  
Cutting Zone

Processing metallic materials by cutting using good electricity conductor cutting edges it appears an electrical current due mainly to the temperature in the cutting zone. Analyzing of the electrical current the information about the unfolding mode of the cutting process can be obtained. The cutting electrical current can be used in several applications: the estimation of the temperature in the cutting zone, the estimation of the cutting forces, the identification of the wear state of the cutting edge etc. The first researches were started in Russia and they were based on the utilization of the cutting electrical current to measure the temperature in the cutting zone. Afterwards, other applications were identified in the literature and the researches were extended in other countries like India, Japan, USA, Brazil, France, Bangladesh and Romania. This paper presents a review of the researches about the electrical current which appears at cutting process.

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 Influence of Extreme Speeds and Rake Angles in Metal Cutting

1963 ◽  
Vol 85 (1) ◽  
pp. 49-64 ◽  
Author(s):  
W. N. Findley ◽  
R. M. Reed
Keyword(s):  
Coefficient Of Friction ◽  
Metal Cutting ◽  
Orthogonal Cutting ◽  
Shear Plane ◽  
Rake Angle ◽  
Lateral Extrusion ◽  
Tool Force ◽  
Steep Decrease ◽  
Peak Value ◽  
Antimony Alloy

A study is presented of the effect of wide variations in speed of cutting and rake angle on orthogonal cutting of several metals—mainly a lead-antimony alloy. It was observed that enormous decreases in tool forces occurred in the lead-antimony with increase in speed from 6 to 3800 fpm, and decrease in rake angle from +30° to −60°. Explanations for these variations are proposed. An unusual observation was that a transition as speed increased from continuous to discontinuous chips occurred at large negative rake angles. Possible causes of this behavior are discussed. Another unusual observation was that a steep rise in tool force occurred with increase in speed for rake angles of 0° and +30°. The rise to a peak value was followed by an equally steep decrease in tool forces. Other observations discussed include the appearance of side spikes on the chips, chip curl, lateral extrusion of chips, influence of normal stress occurring on the shear plane, and the apparent coefficient of friction.

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.

Multi-Constrained Analysis of Metal Cutting and its Application

2013 ◽  
Vol 589-590 ◽  
pp. 38-44
Author(s):  
Gang Liu ◽  
Ming Chen ◽  
Peng Nan Li ◽  
Qing Zhen Bi ◽  
Bao Cai Guo
Keyword(s):  
Thermal Conductivity ◽  
Stainless Steel ◽  
Metal Cutting ◽  
Cutting Tools ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Rake Angle ◽  
Cutting Process ◽  
Optimization Strategy ◽  
First Time

The concept of multi-constrained analysis of the cutting process is presented for the first time in the paper. The paper adopts a method to solve an important problem which is how to judge the influence of constrains during the cutting process. The research results are applied for HSS drills for cutting stainless steel. On the basis of the multi-constrained analysis combined with methods of simulations and standard experiments, the optimum methods are provided for structure, coating and cutting parameters of cutting tools. For geometric structure of tools, optimization is to increase thickness of cutting and rake angle. Coating optimization strategy is choosing high temperature hardness and low thermal conductivity coating. Optimization of cutting parameter is to adjust feed fate, then select proper cutting speed. The conclusion of paper is helpful for the cutting optimization.

Simulation Research on the Metal Cutting Process

2013 ◽  
Vol 641-642 ◽  
pp. 277-280
Author(s):  
Cheng Lei ◽  
Shou Ne Xiao ◽  
Shi Hui Luo
Keyword(s):  
Finite Element ◽  
Metal Cutting ◽  
Three Dimensional ◽  
Element Model ◽  
Rake Angle ◽  
Friction Model ◽  
Cutting Process ◽  
Simulation Research ◽  
Finite Element Software ◽  
Explicit Analysis

The three-dimensional explicit dynamic analysis of metal cutting process is done using the non- linear finite element software LS-DYNA. In the finite element model, 8- node 3D solid element based on one- point integration Lagrangian formulation is adopted, metal material is modeled with Johnson-Cook constitutive model, chip separation is simulated using the material failure criterion of Johnson and Cook proposed and combing the failure element deletion method, friction model of chip-tool contact interface is developed to simultaneously account for sticking and sliding situation. Through explicit analysis, rake angle, cutting depth, and cutting width on the shape of the chip influence are obtained.

Effects of Strain Rate and Temperature in Orthogonal Metal Cutting

1966 ◽  
Vol 8 (3) ◽  
pp. 264-275 ◽  
Author(s):  
G. Boothroyd ◽  
J. A. Bailey
Keyword(s):  
Theoretical Analysis ◽  
Strain Rate ◽  
Metal Cutting ◽  
Single Phase ◽  
Orthogonal Cutting ◽  
Cutting Speed ◽  
Rake Angle ◽  
Cutting Process ◽  
Strain Rates ◽  
Continuous Chip

A new theoretical analysis of the orthogonal cutting process is described which is based on the known behaviour of a single phase metal at high strains, strain rates and temperatures. The theoretical analysis applies to the case where a continuous chip is produced under non-lubricated conditions with the absence of a built-up edge on the tool face and indicates the important parameters in the cutting process. The theory is examined experimentally and its validity established. Finally, from a knowledge of the effects of strain rate and temperature on the yield stress of a single phase metal, the theory is used to predict the effects of changes in cutting speed and tool rake angle on the tool forces and geometry of the cutting process. These predictions are compared qualitatively with the results of cutting tests.

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

2014 ◽  
Vol 939 ◽  
pp. 194-200
Author(s):  
Shamsuddin Sulaiman ◽  
Mohd K.A. Ariffin ◽  
A. Roshan
Keyword(s):  
Finite Element ◽  
Cutting Force ◽  
High Speed ◽  
Metal Cutting ◽  
Rake Angle ◽  
Cutting Process ◽  
High Speed Machining ◽  
Tool Temperature ◽  
Aisi 1045 ◽  
Cutting Speeds

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.

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