A Study of Burr Formation Processes Using the Finite Element Method: Part II—The Influences of Exit Angle, Rake Angle, and Backup Material on Burr Formation Processes

1999 ◽  
Vol 122 (2) ◽  
pp. 229-237 ◽  
Author(s):  
I. W. Park ◽  
D. A. Dornfeld
Keyword(s):  
Finite Element ◽  
Steady State ◽  
Metal Cutting ◽  
Rake Angle ◽  
Plastic Work ◽  
Burr Formation ◽  
Formation Mechanisms ◽  
Exit Angle ◽  
Formation Processes ◽  
Burr Size

Finite element models in orthogonal cutting are presented in order to examine the influences of exit angles of the workpiece, tool rake angles, and backup materials on burr formation processes in 304 L stainless steel in particular. Based on the metal-cutting simulation procedure proposed by the authors, a series of stress and strain contours and final burr/breakout configurations are obtained. The burr formation mechanisms with respect to five different exit angles are found, and duration of the burr formation process increases with an increase of exit angle, resulting in different burr/breakout configurations. Based on the development of negative shear stress in front of the tool tip, the tool tip damage, what is called “chipping,” is investigated. Also, with fixed cutting conditions and workpiece exit geometry, the influence of the rake angle is found to be closely related to the rate of plastic work in steady-state cutting because the larger the rate of plastic work in steady-state cutting, the earlier the burr initiation commences. Furthermore, in order to effectively minimize the burr size, three cases of backup material influences on burr formation processes are examined. It is found that the burr size can be effectively minimized when the backup material supports the workpiece only up to the predefined machined surface. [S0094-4289(00)01402-X]

Finite Element Modeling of Burr Formation in Metal Cutting with a Backup Material

2007 ◽  
Vol 24-25 ◽  
pp. 71-76 ◽  
Author(s):  
Wen Jun Deng ◽  
Wei Xia ◽  
Long Sheng Lu ◽  
Yong Tang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Material Properties ◽  
Metal Cutting ◽  
Element Model ◽  
Burr Formation ◽  
Tool Geometry ◽  
Cutting Condition ◽  
Burr Size ◽  
Initiation And Propagation

2D finite element model with the same material for backup to minimize the burr size was developed to investigate mechanism of burr formation and burr minimization. The flowstress of the workpiece and backup material are taken as a function of strain, strain-rate and temperature. Temperature-dependent material properties are also considered. The Cockroft-Latham damage criterion has been adopted to simulate ductile fracture. The crack initiation and propagation is simulated by deleting the mesh element. The result shows putting a backup material behind the edge of the workpiece is an effective way to minimize the burr size. The effects of cutting condition, temperature and different backup material properties on the burr formation and burr size can be investigated using the developed finite element model. This model could be useful in the search for optimal tool geometry and cutting condition for burr minimization and for the modeling of a burr formation mechanism.

Effect of In-Plane Exit Angle and Rake Angles on Burr Height and Thickness in Face Milling Operation

1999 ◽  
Vol 121 (1) ◽  
pp. 13-19 ◽  
Author(s):  
M. Hashimura ◽  
J. Hassamontr ◽  
D. A. Dornfeld
Keyword(s):  
Three Dimensional ◽  
Rake Angle ◽  
Burr Formation ◽  
Formation Mechanisms ◽  
304L Stainless Steel ◽  
Exit Angle ◽  
Dimensional Effects ◽  
Exit Surface ◽  
Radial Rake Angle ◽  
Exit Burr

Burrs formed by milling are three-dimensional in nature. Therefore the three-dimensional effects on milling burr formation in 304L stainless steel were considered. An important aspect of the three-dimensional effects is the exit order of the tool edges because the burr remains near the final exit position of the tool along the workpiece edge. The geometric parameters of the workpiece and tools were varied to change exit order in the workpiece around the cutting edge. Moreover in this paper, classification of milling burrs based on burr location, shape and mechanism is also proposed to avoid confusion. The milling burrs were classified according to three locations, five shapes and four burr formation mechanisms based on fractography. The exit burr on the exit surface and the side burr on transition surface of workpiece were mainly analyzed. The effect of in-plane exit angle and radial rake angle on burr formation were shown and the burr formation mechanism for each burr was also discussed.

Finite Element Modeling of Burr Formation in Orthogonal Metal Cutting

2008 ◽  
Vol 53-54 ◽  
pp. 71-76 ◽  
Author(s):  
Wen Jun Deng ◽  
C. Li ◽  
Wei Xia ◽  
X.Z. Wei
Keyword(s):  
Finite Element ◽  
Steady State ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Element Model ◽  
Burr Formation ◽  
Cutting Condition ◽  
Simulation Procedure ◽  
Chip Flow ◽  
Orthogonal Metal Cutting

A coupled thermo-mechanical model of plane-strain orthogonal metal cutting including burr formation is presented using the commercial finite element code. A simulation procedure based on Normalized Cockroft-Latham damage criterion is proposed for the purpose of better understanding the burr formation mechanism and obtaining a quantitative analysis of burrs at exit. The cutting process is simulated from the transient initial chip formation state to the steady-state of cutting, and then to tool exit transient chip flow, by incrementally advancing the cutting tool. The effects of cutting condition on the non-steady-state chip flow while tool exit can be investigated using the developed finite element model.

Finite Element Modelling and Analysis of Cutting-Direction Burr Formation

2008 ◽  
Vol 392-394 ◽  
pp. 88-92
Author(s):  
Xiao Wang ◽  
H. Yan ◽  
C. Liang ◽  
B. Wu ◽  
Hui Xia Liu ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Metal Cutting ◽  
Chip Thickness ◽  
Element Model ◽  
Rake Angle ◽  
Burr Formation ◽  
Workpiece Material ◽  
Orthogonal Machining ◽  
Cutting Direction

To prevent or reduce the formation of burr efficiently in metal cutting, it is necessary to reveal the burr formation mechanism. A finite element model of cutting-direction burr formation in orthogonal machining was presented in this paper. The simulation of the burr formation process was conducted. Undeformed chip thickness, rake angle, rounded cutting edge radius and workpiece material were included in cutting conditions, whose influences on burr formation were investigated, according to the simulation results. By comparing the results of the simulation and the experiment, good consistency is achieved which proves that the finite element model of burr formation in this paper is significant and effective to predict burr formation.

Burr Size Minimization When Drilling 6061-T6 Aluminum Alloy

2012 ◽  
Author(s):  
Y. Zedan ◽  
S. A. Niknam ◽  
A. Djebara ◽  
V. Songmene
Keyword(s):  
Process Parameters ◽  
Cutting Speed ◽  
Cutting Conditions ◽  
Cutting Fluid ◽  
Burr Formation ◽  
Formation Mechanisms ◽  
Regression Equations ◽  
Taguchi Optimization ◽  
Burr Height ◽  
Burr Size

The burr formation mechanisms strongly depend on the machining methods as well as cutting conditions. Cutting fluids play significant roles in machining, including reduction of friction and temperature. Using a cutting fluid, however, degrades the quality of the environment and increases machining costs. In the present work, initially the effects of cutting fluid application (dry, mist and flood) and their interaction with cutting parameters on the burr size during drilling of 6061-T6 aluminum alloys were investigated using multi-level full factorial design. Second-order non-linear mathematical models were developed to predict burr height for various lubrication modes. The accuracy of the regression equations formulated to predict burr height when using different lubrication modes has been verified through carrying out random experiments in the range of variation of these variables. A procedure was developed to minimize burr size for drilling holes by presenting the optimal levels of process parameters. Taguchi optimization method based on L9 orthogonal array design of experiment was then used which has shown very accurate process parameters selection that leads to minimum burr height. According to experimental study, it was observed that dry and mist drilling can produce parts with quality comparable with those obtained in wet drilling when using the optimal cutting conditions. In addition, increase in cutting speed and feed rate exhibits a decrease in burr size.

Burr Formation in Metal Cutting Operations and some Deburring Methods

2013 ◽  
Vol 581 ◽  
pp. 235-240
Author(s):  
János Kodácsy ◽  
András Szabó
Keyword(s):  
Production Process ◽  
Sheet Metal ◽  
Metal Cutting ◽  
Burr Formation ◽  
Formation Mechanisms ◽  
Mechanical Process ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Quality Of Products

Remained burrs on edges of the parts after metal cutting operations may cause many problems in the production process and in the quality of products, therefore the burrs must be completely removed. In the paper, the authors give an outline of the elements and the technical and economical influences of the burr formation, and the characteristics of the burrs and the burr formation mechanisms. The authors present some special processes that are suitable for deburring of small pieces (e.g. Magnetic Abrasive Deburring), and a frequently applied mechanical process: power brushing. The authors have carried out many investigations regarding the magnetic abrasive deburring of small, blanked sheet metal parts, furthermore the machine deburring of large-sized metal workpieces by carbide-reinforced cylindrical brushes. The detailed conditions, data, results and conclusions of these deburring experiments are treated in the paper too.

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.

A Study of Burr Formation Processes Using the Finite Element Method: Part I

1999 ◽  
Vol 122 (2) ◽  
pp. 221-228 ◽  
Author(s):  
I. W. Park ◽  
D. A. Dornfeld
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Metal Cutting ◽  
Ductile Failure ◽  
Development Stage ◽  
Burr Formation ◽  
The Finite Element Method ◽  
Initial Development ◽  
Final Development ◽  
Element Method

A finite element model of orthogonal metal cutting including burr formation is presented. A metal-cutting simulation procedure based on a ductile failure criterion is proposed for the purpose of better understanding the burr formation mechanism and obtaining a quantitative analysis of burrs using the finite element method. In this study, the four stages of burr formation, i.e., initiation, initial development, pivoting point, and final development stages, are investigated based on the stress and strain contours with the progressive change of geometry at the edge of the workpiece. Also, the characteristics of thick and thin burrs are clarified along with the negative deformation zone formed in front of the tool edge in the final development stage. [S0094-4289(00)00702-7]

An explicit finite element model to study the influence of rake angle and friction during orthogonal metal cutting

2014 ◽  
Vol 73 (5-8) ◽  
pp. 875-885 ◽  
Author(s):  
Pradeep L. Menezes ◽  
Ilya V. Avdeev ◽  
Michael R. Lovell ◽  
C. Fred Higgs
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Metal Cutting ◽  
Element Model ◽  
Rake Angle ◽  
Explicit Finite Element ◽  
Orthogonal Metal Cutting

Comparison Orthogonal Tube Turning Data Versus Finite Element Simulation Using LS Dyna

2013 ◽  
Author(s):  
Vishnu Vardhan Chandrasekaran ◽  
Lewis N. Payton
Keyword(s):  
Finite Element ◽  
Metal Cutting ◽  
Tool Material ◽  
Element Model ◽  
Rake Angle ◽  
Machining Process ◽  
Work Piece ◽  
Orthogonal Machining ◽  
Work Material ◽  
Cut Depth

The current study focuses on building a 2-Dimensional finite element model to simulate the orthogonal machining process under a dry machining environment in a commercially available FEA solver LS DYNA. One of the key objectives of this thesis is to carefully document the use of LS Dyna to model metal cutting, allowing other researchers to more quickly build on this work. Actual force data is obtained using an Orthogonal Tube Turning apparatus that has been statistically validated to an accuracy of 99+%. The work material used in this study is Aluminum 6061-T6 alloy. The tool material is tool steel, which is modeled as a rigid body. A Plastic Kinematic Material Hardening model is used to define the work material. Chip formation is based on the effective failure plastic strain. A constant coefficient of friction between the tool and work piece is used, obtained from the actual experimental results. The simulation is carried out with the same constant velocity, different rake angles and depth cuts as in the real world experiment. The cutting force and thrust force values obtained for each combination of rake angle and cut depth are validated against the experimental data obtained at Auburn University. The resulting model is considered valid enough to use for sensitivity analysis of the metal cutting process in aluminum alloy 6061-T6 in the university environment. The model is available publicly to any university from a website provided.

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