3D finite element prediction of chip flow, burr formation, and cutting forces in micro end-milling of aluminum 6061-T6

doi:10.1007/s11465-017-0421-6

Front. Mech. Eng.

2017, Vol. 12

Issue (2) : 203-214 https://doi.org/10.1007/s11465-017-0421-6

RESEARCH ARTICLE

3D finite element prediction of chip flow, burr formation, and cutting forces in micro end-milling of aluminum 6061-T6

A. DAVOUDINEJAD(

), P. PARENTI, M. ANNONI

Mechanical Engineering Department, Politecnico di Milano, Milan 20156, Italy

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Abstract

Predictive models for machining operations have been significantly improved through numerous methods in recent decades. This study proposed a 3D finite element modeling (3D FEM) approach for the micro end-milling of Al6061-T6. Finite element (FE) simulations were performed under different cutting conditions to obtain realistic numerical predictions of chip flow, burr formation, and cutting forces. FE modeling displayed notable advantages, such as capability to easily handle any type of tool geometry and any side effect on chip formation, including thermal aspect and material property changes. The proposed 3D FE model considers the effects of mill helix angle and cutting edge radius on the chip. The prediction capability of the FE model was validated by comparing numerical model and experimental test results. Burr dimension trends were correlated with force profile shapes. However, the FE predictions overestimated the real force magnitude. This overestimation indicates that the model requires further development.

Keywords 3D finite element modeling micro end-milling cutting force chip formation burr formation

Corresponding Author(s): A. DAVOUDINEJAD

Just Accepted Date: 21 February 2017 Online First Date: 21 March 2017 Issue Date: 19 June 2017

Cite this article:

A. DAVOUDINEJAD,P. PARENTI,M. ANNONI. 3D finite element prediction of chip flow, burr formation, and cutting forces in micro end-milling of aluminum 6061-T6[J]. Front. Mech. Eng., 2017, 12(2): 203-214.

URL:

https://academic.hep.com.cn/fme/EN/10.1007/s11465-017-0421-6
https://academic.hep.com.cn/fme/EN/Y2017/V12/I2/203

Tab.1 Nominal and actual tool characteristics

Fig.1 (a) FEM simulation setup; (b) cutting edge magnification; (c) definition of tool engagement angle q (top view)

Fig.2 (a) Machine tool; (b) workpiece fixture on the dynamometer to measure the cutting forces; (c) workpiece machining area (top view)

Fig.3 Characterization of the tool geometry for modeling the micro end-mill: (a) Measuring positions along the mill axis; (b) mill and core diameters and cutting edge radius measured on Slice 2; (c) helix angle

Tab.2 Experimental conditions

Fig.4 Frequency response functions (FRF) resulting from impact tests on the fixturing and force measurement system

Fig.5 (a) Schematic of the undeformed chip section along the periphery of tool; (b) schematic of the 3D undeformed chip geometry; (c) FEM chip formation for Test 2 (f_z = 2 µm/(tooth·revolution); v_c = 28.27 m/min); (d) experimental chip

Fig.6 Plastic strain distribution in the workpiece, chip, and burr at (a) Test 1 (f_z=4 µm/(tooth·revolution); v_c=28.27 m/min), (b) Test 2 (f_z=2 µm/(tooth·revolution); v_c=28.27 m/min), (c) Test 3 (f_z=4 µm/(tooth·revolution); v_c=14.13 m/min), and (d) Test 4 (f_z=2 µm/(tooth·revolution); v_c=14.13 m/min)

Fig.7 Chip formation and temperature distribution at different engagement angles: (a) Test 2 (f_z=2 µm/(tooth·revolution); v_c=28.27 m/min); (b) Test 3 (f_z = 4 µm/(tooth·revolution); v_c=14.13 m/min)

Fig.8 Temperature distribution along the cutting edge and chip in (a) Test 1 (f_z=4 µm/(tooth·revolution); v_c=28.27 m/min), (b) Test 2 (f_z=2 µm/(tooth·revolution); v_c=28.27 m/min), (c) Test 3 (f_z=4 µm/(tooth·revolution); v_c=14.13 m/min), and (d) Test 4 (f_z=2 µm/(tooth·revolution); v_c=14.13 m/min)

Fig.9 Top view of burr formation in (a) Test 1 (f_z=4 µm/(tooth·revolution); v_c=28.27 m/min), (b) Test 2 (f_z=2 µm/(tooth·revolution); v_c=28.27 m/min), (c) Test 3 (f_z=4 µm/(tooth·revolution); v_c=14.13 m/min), and (d) Test 4 (f_z=2 µm/(tooth·revolution); v_c=14.13 m/min)

Fig.10 Cutting force comparison for Test 1 (f_z=4 µm/(tooth·revolution); v_c=28.27 m/min; a_p=0.05 mm). (a) Experimental cutting forces; (b) FEM cutting forces

Fig.11 Cutting force comparison for Test 3 (f_z=4 µm/(tooth·revolution); v_c=14.13 m/min; a_p=0.05 mm). (a) Experimental cutting forces; (b) FEM cutting forces

a_e	Width of cut
a_p	Depth of cut
c₀, c₁, c₂, c₃, c₄, c₅	Coefficients for the polynomial fit
f_z	Feed per tooth
F_x,F_y,F_z	Cutting force components along the machine tool axes
g(e^p)	Isotropic strain hardening
M	Strain rate sensitivity coefficient
N	Strain hardening exponent
n	Spindle speed
P	Total amount of acquired force points
r_e	Cutting edge radius
r_e	Corner radius
t_n	Undeformed chip thickness
T	Temperature
v_c	Cutting speed
Γ(e)	Strain rate sensitivity
e^p	Plastic strain
$ε 0 p$	Reference plastic strain
$ε ˙$	Strain rate
$ε ˙ 0$	Reference plastic strain rate
q	Tool engagement angle
Q(T)	Fifth order polynomial function for thermal softening
m	Friction coefficient
s₀	Initial yield stress
s_n	Normal stress
t	Frictional stress

1	Li H, Lai X, Li C, et al.. Development of meso-scale milling machine tool and its performance analysis. Frontiers of Mechanical Engineering in China, 2008, 3(1): 59–65 https://doi.org/10.1007/s11465-008-0005-6
2	Masuzawa T. State of the art of micromachining. CIRP Annals—Manufacturing Technology, 2000, 49(2): 473–488 https://doi.org/10.1016/S0007-8506(07)63451-9
3	Liu X, DeVor R E, Kapoor S G. An analytical model for the prediction of minimum chip thickness in micromachining. Journal of Manufacturing Science and Engineering, 2005, 128(2): 474–481 https://doi.org/10.1115/1.2162905
4	Bao W Y, Tansel I N. Modeling micro-end-milling operations. Part I: Analytical cutting force model. International Journal of Machine Tools and Manufacture, 2000, 40(15): 2155–2173 https://doi.org/10.1016/S0890-6955(00)00054-7
5	Arrazola P J, Özel T, Umbrello D, et al.. Recent advances in modelling of metal machining processes. CIRP Annals—Manufacturing Technology, 2013, 62(2): 695–718 https://doi.org/10.1016/j.cirp.2013.05.006
6	Maurel-Pantel A, Fontaine M, Thibaud S, et al.. 3D FEM simulations of shoulder milling operations on a 304L stainless steel. Simulation Modelling Practice and Theory, 2012, 22(3): 13–27 https://doi.org/10.1016/j.simpat.2011.10.009
7	Rubio L, De la Sen M, Longstaff A P, et al.. Analysis of discrete time schemes for milling forces control under fractional order holds. International Journal of Precision Engineering and Manufacturing, 2013, 14(5): 735–744 https://doi.org/10.1007/s12541-013-0097-8
8	Özel T, Altan T. Modeling of high speed machining processes for predicting tool forces, stresses and temperatures using FEM simulations. In: Proceedings of the CIRP International Workshop on Modeling of Machining Operations. Atlanta, 1998
9	Özel T, Altan T. Process simulation using finite element method prediction of cutting forces, tool stresses and temperatures in high-speed flat end milling. International Journal of Machine Tools and Manufacture, 2000, 40(5): 713–738 https://doi.org/10.1016/S0890-6955(99)00080-2
10	Liu K, Melkote S N. Finite element analysis of the influence of tool edge radius on size effect in orthogonal micro-cutting process. International Journal of Mechanical Sciences, 2007, 49(5): 650–660 https://doi.org/10.1016/j.ijmecsci.2006.09.012
11	Nasr M N A, Ng E G, Elbestawi M A. Modelling the effects of tool-edge radius on residual stresses when orthogonal cutting AISI 316L. International Journal of Machine Tools and Manufacture, 2007, 47(2): 401–411 https://doi.org/10.1016/j.ijmachtools.2006.03.004
12	Afazov S M, Ratchev S M, Segal J. Modelling and simulation of micro-milling cutting forces. Journal of Materials Processing Technology, 2010, 210(15): 2154–2162 https://doi.org/10.1016/j.jmatprotec.2010.07.033
13	Özel T, Liu X, Dhanorker A. Modelling and simulation of micro-milling process. In: Proceedings of the 4th International Conference and Exhibition on Design and Production of Machines and Dies/Molds. 2007
14	Jin X, Altintas Y. Prediction of micro-milling forces with finite element method. Journal of Materials Processing Technology, 2012, 212(3): 542–552 https://doi.org/10.1016/j.jmatprotec.2011.05.020
15	Thepsonthi T, Özel T. Experimental and finite element simulation based investigations on micro-milling Ti-6Al-4V titanium alloy: Effects of cBN coating on tool wear. Journal of Materials Processing Technology, 2013, 213(4): 532–542 https://doi.org/10.1016/j.jmatprotec.2012.11.003
16	Woon K S, Rahman M, Neo K S, et al.. The effect of tool edge radius on the contact phenomenon of tool-based micromachining. International Journal of Machine Tools and Manufacture, 2008, 48(12–13): 1395–1407 https://doi.org/10.1016/j.ijmachtools.2008.05.001
17	Wu H, Zhang S. 3D FEM simulation of milling process for titanium alloy Ti6Al4V. International Journal of Advanced Manufacturing Technology, 2014, 71(5–8): 1319–1326 https://doi.org/10.1007/s00170-013-5546-0
18	Yang K, Liang Y, Zheng K, et al.. Tool edge radius effect on cutting temperature in micro-end-milling process. International Journal of Advanced Manufacturing Technology, 2011, 52(9–12): 905–912 https://doi.org/10.1007/s00170-010-2795-z
19	Thepsonthi T, Özel T. 3-D finite element process simulation of micro-end milling Ti-6Al-4V titanium alloy: Experimental validations on chip flow and tool wear. Journal of Materials Processing Technology, 2015, 221: 128–145 https://doi.org/10.1016/j.jmatprotec.2015.02.019
20	Chen, M, Ni H, Wang Z, et al.. Research on the modeling of burr formation process in micro-ball end milling operation on Ti-6Al-4V. International Journal of Advanced Manufacturing Technology, 2012, 62(9): 901–912
21	Advantedge T W.User manual for Third Wave AdvantEdge Version 6.2.011, USA
22	Man X, Ren D, Usui S, et al.. Validation of finite element cutting force prediction for end milling. Procedia CIRP, 2012, 1: 663–668 https://doi.org/10.1016/j.procir.2012.05.019
23	Davoudinejad A, Chiappini E, Tirelli S, et al.. Finite element simulation and validation of chip formation and cutting force in dry and cryogenic cutting of Ti-6Al-4V. Procedia Manufacturing, 2015, 1: 728–739 https://doi.org/10.1016/j.promfg.2015.09.037
24	Arrazola P J, Özel T. Investigations on the effects of friction modeling in finite element simulation of machining. International Journal of Mechanical Sciences, 2010, 52(1): 31–42 https://doi.org/10.1016/j.ijmecsci.2009.10.001
25	Özel T. The influence of friction models on finite element simulations of machining. International Journal of Machine Tools and Manufacture, 2006, 46(5): 518–530 https://doi.org/10.1016/j.ijmachtools.2005.07.001
26	Kim K W, Lee W Y, Sin H C. A finite element analysis for the characteristics of temperature and stress in micro-machining considering the size effect. International Journal of Machine Tools and Manufacture, 1999, 39(9): 1507–1524 https://doi.org/10.1016/S0890-6955(98)00071-6
27	Al-Qutub A M, Khalil A, Saheb N, et al.. Wear and friction behavior of Al6061 alloy reinforced with carbon nanotubes. Wear, 2013, 297(1–2): 752–761 https://doi.org/10.1016/j.wear.2012.10.006
28	Bathurst S P, Kim S G. Designing direct printing process for improved piezoelectric micro-devices. CIRP Annals—Manufacturing Technology, 2009, 58(1): 193–196 https://doi.org/10.1016/j.cirp.2009.03.016
29	Annoni M, Pusterla N, Rebaioli L, et al.. Calibration and validation of a mechanistic micromilling force prediction model. Journal of Manufacturing Science and Engineering, 2015, 138(1): 011001 https://doi.org/10.1115/1.4030210
30	Hashimura M, Hassamontr J, Dornfeld D A. Effect of in-plane exit angle and rake angles on burr height and thickness in face milling operation. Journal of Manufacturing Science and Engineering, 1999, 121(1): 13–19 https://doi.org/10.1115/1.2830566
31	Davoudinejad A. 3D finite element modeling of micro end-milling by considering tool run-out, temperature distribution, chip and burr formation. Dissertation for the Doctoral Degree. Milan: Polytechnic University of Milan, 2016
32	JohnsonG R, Cook W H. A constitutive model and data for metals subjected to large strains, high strain rates and high temperatures. In: Proceedings of the 7th International Symposium on Ballistics. The Hague, 1983, 541–547
33	Calamaz M, Coupard D, Girot F. A new material model for 2D numerical simulation of serrated chip formation when machining titanium alloy Ti-6Al-4V. International Journal of Machine Tools and Manufacture, 2008, 48(3–4): 275–288 https://doi.org/10.1016/j.ijmachtools.2007.10.014

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