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Research Papers

Microhardness Prediction Based on a Microstructure-Sensitive Flow Stress Model During High Speed Machining Ti-6Al-4V

[+] Author and Article Information
Qingqing Wang

Key Laboratory of High Efficiency and
Clean Mechanical Manufacture of MOE,
School of Mechanical Engineering,
Shandong University,
Jinan 250061, China;
Key National Demonstration Center for
Experimental Mechanical Engineering
Education,
Shandong University,
Jinan 250061, China

Zhanqiang Liu

Key Laboratory of High Efficiency and
Clean Mechanical Manufacture of MOE,
School of Mechanical Engineering,
Shandong University,
Jinan 250061, China;
Key National Demonstration Center for
Experimental Mechanical Engineering Education,
Shandong University,
Jinan 250061, China
e-mail: melius@sdu.edu.cn

1Corresponding author.

Manuscript received December 18, 2017; final manuscript received March 24, 2018; published online June 8, 2018. Assoc. Editor: Guillaume Fromentin.

J. Manuf. Sci. Eng 140(9), 091003 (Jun 08, 2018) (15 pages) Paper No: MANU-17-1789; doi: 10.1115/1.4039889 History: Received December 18, 2017; Revised March 24, 2018

Exploring the hardening mechanisms during high speed machining (HSM) is an effective approach to improve the fatigue strength and the wear resistance of machined surface and to control the fragmentation of chips in a certain range of hardness. In this paper, the microhardness variation is explored from the perspective of microstructural evolutions, as a direct consequence of the severe deformation during HSM Ti-6Al-4V alloy. A microstructure-sensitive flow stress model coupled the phenomena of grain refinement, deformation twinning, and phase transformations is first proposed. Then the microstructure-sensitive flow stress model is implemented into the cutting simulation model via a user-defined subroutine to analyze the flow stress variation induced by the microstructure evolutions during HSM Ti-6Al-4V. Finally, the relationship between the microhardness and flow stress is developed and modified based on the classical theory that the hardness is directly proportional to the flow stress. The study shows that the deformation twinning (generated at higher cutting speeds) plays a more important role in the hardening of Ti-6Al-4V compared with the grain refinement and phase transformation. The predicted microhardness distributions align well with the measured values. It provides a novel thinking that it is plausible to obtain a high microhardness material via controlling the microstructure alterations during machining process.

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References

Zhang, D. , Zhang, X. M. , Leopold, J. , and Ding, H. , 2017, “ Subsurface Deformation Generated by Orthogonal Cutting: Analytical Modeling and Experimental Verification,” ASME J. Manuf. Sci. Eng., 139(9), p. 094502. [CrossRef]
Shen, N. G. , and Ding, H. T. , 2014, “ Physics-Based Microstructure Simulation for Drilled Hole Surface in Hardened Steel,” ASME J. Manuf. Sci. Eng., 136(4), p. 044504. [CrossRef]
Zhang, X. M. , Chen, L. , and Ding, H. , 2016, “ Effects of Process Parameters on White Layer Formation and Morphology in Hard Turning of AISI52100 Steel,” ASME J. Manuf. Sci. Eng., 138(7), p. 074502. [CrossRef]
Wang, Q. Q. , and Liu, Z. Q. , 2016, “ Plastic Deformation Induced Nano-Scale Twins in Ti-6Al-4V Machined Surface With High Speed Machining,” Mater. Sci. Eng. A, 675, pp. 271–279. [CrossRef]
Ding, H. T. , and Shin, Y. C. , 2012, “ A Metallo-Thermomechanically Coupled Analysis of Orthogonal Cutting of AISI 1045 Steel,” ASME J. Manuf. Sci. Eng., 134(5), p. 051014. [CrossRef]
Shen, N. G. , Ding, H. T. , Pu, Z. W. , Jawahir, I. S. , and Jia, T. , 2017, “ Enhanced Surface Integrity From Cryogenic Machining of AZ31B Mg Alloy: A Physics-Based Analysis With Microstructure Prediction,” ASME J. Manuf. Sci. Eng., 139(6), p. 061012. [CrossRef]
Wang, B. , Liu, Z. Q. , Su, G. S. , and Ai, X. , 2015, “ Brittle Removal Mechanism of Ductile Materials With Ultrahigh-Speed Machining,” ASME J. Manuf. Sci. Eng., 137(6), p. 061002. [CrossRef]
Zhang, X. P. , Shivpuri, R. , and Srivastava, A. K. , 2016, “ Chip Fracture Behavior in the High Speed Machining of Titanium Alloys,” ASME J. Manuf. Sci. Eng., 138(8), p. 081001. [CrossRef]
Rotella , G., Jr. , Dillon, O. W. , Umbrello, D. , Settineri, L. , and Jawahir, I. S. , 2013, “ Finite Element Modeling of Microstructural Changes in Turning of AA7075-T651 Alloy,” J. Manuf. Process., 15(1), pp. 87–95. [CrossRef]
Rotella, G. , and Umbrello, D. , 2014, “ Finite Element Modeling of Microstructural Changes in Dry and Cryogenic Cutting of Ti6Al4V Alloy,” CIRP Ann.-Manuf. Technol., 63(1), pp. 69–72. [CrossRef]
Liu, R. , Salahshoor, M. , Melkote, S. N. , and Marusich, T. , 2014, “ The Prediction of Machined Surface Hardness Using a New Physics-Based Material Model,” Proc. CIRP, 13, pp. 249–256.
Nguyen, T. , and Zhang, L. C. , 2010, “ Grinding-Hardening Using Dry Air and Liquid Nitrogen: Prediction and Verification of Temperature Fields and Hardened Layer Thickness,” Int. J. Mach. Tools Manuf., 50(10), pp. 901–910. [CrossRef]
Ding, H. T. , and Shin, Y. C. , 2013, “ Multi-Physics Modeling and Simulations of Surface Microstructure Alteration in Hard Turning,” J. Mater. Process. Technol., 213(6), pp. 877–886. [CrossRef]
Velásquez, J. D. P. , Tidua, A. , Bollea, B. , Chevrier, P. , and Fundenberger, J. J. , 2010, “ Sub-Surface and Surface Analysis of High Speed Machined Ti-6Al-4V Alloy,” Mater. Sci. Eng. A, 527(10–11), pp. 2572–2578. [CrossRef]
Zhang, X. P. , Shivpuri, R. , and Srivastava, A. K. , 2017, “ A New Microstructure-Sensitive Flow Stress Model for the High-Speed Machining of Titanium Alloy Ti-6Al-4V,” ASME J. Manuf. Sci. Eng., 139(5), p. 051006. [CrossRef]
Pan, Z. P. , Liang, S. Y. , Garmestani, H. , and Shih, D. S. , 2016, “ Prediction of Machining-Induced Phase Transformation and Grain Growth of Ti-6Al-4V Alloy,” Int. J. Adv. Manuf. Technol., 87(1–4), pp. 859–866. [CrossRef]
Wang, Q. Q. , Liu, Z. Q. , Wang, B. , Song, Q. H. , and Wan, Y. , 2016, “ Evolutions of Grain Size and Micro-Hardness During Chip Formation and Machined Surface Generation for Ti-6Al-4V in High-Speed Machining,” Int. J. Adv. Manuf. Technol., 82(9–12), pp. 1725–1736. [CrossRef]
Kim, J. H. , Semiatin, S. L. , Lee, Y. H. , and Lee, C. S. , 2011, “ A Self-Consistent Approach for Modeling the Flow Behavior of the Alpha and Beta Phases in Ti-6Al-4V,” Metall. Mater. Trans. A, 42A(7), pp. 1805–1814. [CrossRef]
Kim, I. , Kim, J. , Shin, D. H. , Liao, X. Z. , and Zhu, Y. T. , 2003, “ Deformation Twins in Pure Titanium Processed by Equal Channel Angular Pressing,” Scr. Mater., 48(6), pp. 813–817. [CrossRef]
Salem, A. A. , Kalidindi, S. R. , and Doherty, R. D. , 2002, “ Strain Hardening Regimes and Microstructure Evolution During Large Strain Compression of High Purity Titanium,” Scr. Mater., 46(6), pp. 419–423. [CrossRef]
Salem, A. A. , Kalidindi, S. R. , and Doherty, R. D. , 2003, “ Strain Hardening of Titanium: Role of Deformation Twinning,” Acta Mater., 51(4), pp. 4225–4237. [CrossRef]
Kalidindi, S. R. , Salem, A. A. , and Doherty, R. D. , 2003, “ Role of Deformation Twinning on Strain Hardening in Cubic and Hexagonal Polycrystalline Metals,” Adv. Eng. Mater., 5(4), pp. 229–232. [CrossRef]
Salem, A. A. , Kalidindi, S. R. , Doherty, R. D. , and Semiatin, S. L. , 2006, “ Strain Hardening Due to Deformation Twinning in α-Titanium: Mechanisms,” Metall. Mater. Trans. A, 37(1), pp. 259–268. [CrossRef]
Ahn, K. , Huh, H. , and Yoon, J. , 2013, “ Strain Hardening Model of Pure Titanium Considering Effects of Deformation Twinning,” Met. Mater. Int., 19(4), pp. 749–758. [CrossRef]
Tadano, Y. , Yoshihara, Y. , and Hagihara, S. , 2016, “ A Crystal Plasticity Modeling Considering Volume Fraction of Deformation Twinning,” Int. J. Plast., 84, pp. 88–101. [CrossRef]
Salem, A. A. , Kalidindi, S. R. , and Semiatin, S. L. , 2005, “ Strain Hardening Due to Deformation Twinning in α-Titanium: Constitutive Relations and Crystal-Plasticity Modeling,” Acta Mater., 53(12), pp. 3495–3502. [CrossRef]
Meyers, M. A. , Benson, D. J. , Vöhringer, O. , Kad, B. K. , Xue, Q. , and Fu, H. H. , 2002, “ Constitutive Description of Dynamic Deformation: Physically-Based Mechanisms,” Mater. Sci. Eng. A, 322(1–2), pp. 194–216. [CrossRef]
Meyers, M. A. , Voehringer, O. , and Chen, Y. J. , 1999, “ A Constitutive Description of the Slip-Twinning Transition in Metals,” Advances in Twinning, S. Ankem , and C. S. Pande , eds., The Minerals, Metals & Materials Society, Warrendale, PA, pp. 43–65. [PubMed] [PubMed]
Conrad, H. M. , Doner, M. , and Meester, B. D. , 1973, “ Critical Review Deformation and Fracture,” International Conference on Titanium, Proceedings of Titanium Science and Technology, pp. 969–1005.
Ahn, K. , Huh, H. , and Yoon, J. , 2015, “ Rate-Dependent Hardening Model for Pure Titanium Considering the Effect of Deformation Twinning,” Int. J. Mech. Sci., 98, pp. 80–92. [CrossRef]
Wang, Q. Q. , Liu, Z. Q. , Yang, D. , and Mohsan, A. U. H. , 2017, “ Metallurgical-Based Prediction of Stress-Temperature Induced Rapid Heating and Cooling Phase Transformations for High Speed Machining Ti-6Al-4V Alloy,” Mater. Des., 119, pp. 208–218. [CrossRef]
Wan, Z. P. , Zhu, Y. E. , Liu, H. W. , and Tang, Y. , 2012, “ Microstructure Evolution of Adiabatic Shear Bands and Mechanisms of Saw-Tooth Chip Formation in Machining Ti6Al4V,” Mater. Sci. Eng. A, 531, pp. 155–163. [CrossRef]
Semiatin, S. L. , Montheillet, F. , Shen, G. , and Jonas, J. J. , 2002, “ Self-Consistent Modeling of the Flow Behavior of Wrought Alpha/Beta Titanium Alloys Under Isothermal and Nonisothermal Hot-Working Conditions,” Metall. Mater. Trans. A, 33A(8), pp. 2719–2727. [CrossRef]
Fan, Y. , Cheng, P. , Yao, Y. L. , Yang, Z. , and Egland, K. , 2005, “ Effect of Phase Transformations on Laser Forming of Ti-6Al-4V Alloy,” J. Appl. Phys., 98(1), p. 01351801. [CrossRef]
Chan, K. S. , and Lee, Y. D. , 2008, “ Effects of Deformation-Induced Constraint on High-Cycle Fatigue in Ti Alloys With a Duplex Microstructure,” Metall. Mater. Trans. A, 39A(7), pp. 1665–1675. [CrossRef]
Lee, W. S. , and Lin, C. F. , 1998, “ High-Temperature Deformation Behavior of Ti-6Al-4V Alloy Evaluated by High Strain-Rate Compression Tests,” J. Mater. Process. Technol., 75(1–3), pp. 127–136. [CrossRef]
Johnson, G. R. , and Holmquist, T. J. , 1989, “ Test Data and Computational Strengthen and Fracture Model Constants for 23 Materials Subjected to Large Strain, High-Strain Rates, and High Temperatures,” Los Alamos National Laboratory, Los Alamos, NM, Report No. LA-11463-MS.
Arrazola, P. J. , Özel, T. , Umbrello, D. , Davies, M. , and Jawahir, I. S. , 2013, “ Recent Advances in Modeling of Metal Machining Processes,” CIRP Ann.-Manuf. Technol., 62(2), pp. 695–718.
Khodabakhshi, F. , Haghshenas, M. , Eskandari, H. , and Koohbor, B. , 2015, “ Hardness Strength Relationships in Fine and Ultra-Fine Grained Metals Processed Through Constrained Groove Pressing,” Mater. Sci. Eng. A, 636, pp. 331–339. [CrossRef]
Pavlina, E. J. , and Tyne, C. J. V. , 2008, “ Correlation of Yield Strength and Tensile Strength With Hardness for Steels,” J. Mater. Eng. Perform., 17(6), pp. 888–893. [CrossRef]
Elmadagli, M. , and Alpas, A. T. , 2003, “ Metallographic Analysis of the Deformation Microstructure of Copper Subjected to Orthogonal Cutting,” Mater. Sci. Eng. A, 355(1–2), pp. 249–259. [CrossRef]
Krishna, S. C. , Gangwar, N. K. , Jha, A. K. , and Pant, B. , 2013, “ On the Prediction of Strength From Hardness for Copper Alloys,” J. Mater., 2013, p. 352578.
Tabei, A. , Shih, D. S. , Garmestani, H. , and Liang, S. Y. , 2016, “ Dynamic Recrystallization of Al Alloy 7075 in Turning,” ASME J. Manuf. Sci. Eng., 138(7), p. 071010. [CrossRef]
Yoo, M. H. , 1981, “ Slip, Twinning, and Fracture in Hexagonal Close-Packed Metals,” Metall. Mater. Trans. A, 12A(3), pp. 409–418. [CrossRef]
Zhang, X. P. , Shivpuri, R. , and Srivastava, A. K. , 2014, “ Role of Phase Transformation in Chip Segmentation During High Speed Machining of Dual Phase Titanium Alloys,” J. Mater. Process. Technol., 214(12), pp. 3048–3066. [CrossRef]
Rotella, G. , Dillon, O. W. , Umbrello, D. , and Settineri, L. , 2014, “ The Effects of Cooling Conditions on Surface Integrity in Machining of Ti6Al4V Alloy,” Int. J. Adv. Manuf. Technol., 71(1–4), pp. 47–55. [CrossRef]
Chaudhri, M. M. , 1988, “ Subsurface Strain Distribution Around Vickers Hardness Indentations in Annealed Polycrystalline Copper,” Acta Mater., 46(9), pp. 3047–3056. [CrossRef]

Figures

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Fig. 1

Different deformation scales of materials during plastic deformation

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Fig. 2

Research scope of the present work

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Fig. 3

Effect of temperature on CRSS for different twinning modes at strain rate 0.0001 s−1 [29]

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Fig. 4

Variation of deformation twinning volume fraction as a function of flow stress

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Fig. 5

Scanning electron microscope image of Ti-6Al-4V alloy

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Fig. 6

Setup of orthogonal cutting test

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Fig. 7

Experimental procedures: (a) schematic diagram of test areas of microstructure characterizations and (b) schematic diagram of microhardness measurement at the shear bands of serrated chips

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Fig. 8

Geometry dimensions of the cutting simulation model including the boundary conditions

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Fig. 9

Flowchart of the user subroutines for predicting the microhardness variation

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Fig. 10

Calculation models of flow stress in chips: (a) continuous chips, (b) serrated chips, and (c) resolution of resultant cutting forces

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Fig. 11

The fitted relation between the constant C and the effective strain

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Fig. 12

Comparison of experimental and simulated of grain size in the serrated chips at the cutting speed of 200 m/min [17]: (a) simulated result of grain size distribution in serrated chips, (b) experimental result of grain size in a segmented chip, and (c) the enlarged image of shear band marked in (b)

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Fig. 13

The flow stress increment induced by grain refinement: (a) stress variation contour induced by grain refinement at the cutting speed of 500 m/min and (b) stress evolutions caused by grain refinement at various cutting speeds

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Fig. 14

Comparison of experimental and simulated of twin volume fraction in the serrated chips at the cutting speed of 500 m/min: (a) simulated result of twin fraction distribution in serrated chips, (b) experimental result of deformation twinning in a segmented chip, and (c) high revolution TEM image of the detecting area A marked in (b)

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Fig. 15

Stress variation caused by the onset of deformation twinning: (a) the stress variation nephogram induced by deformation twinning at the cutting speed of 500 m/min and (b) twinning induced hardening at different cutting speeds

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Fig. 16

Verification of the β phase variation in the rapid heating process during HSM of Ti-6Al-4V [31] (Reprinted with permission from Elsevier @ 2017): (a) the predicted result of Zhang et al. [45] (Reprinted with permission from Elsevier @ 2014) and (b) the predicted results of β phase variation in our paper

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Fig. 17

Phase transformation of α-Ti to β-Ti induced the stress variation in the heating process of HSM Ti-6Al-4V: (a) flow stress contour induced by phase transformation in the rapid heating process at the cutting speed of 500 m/min and (b) phase transformation of α-Ti to β-Ti-induced flow stress variations at various cutting speeds

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Fig. 18

Evolutions of α″ phase volume fraction during rapid cooling process cutting speed of 500 m/min [31]: (a) serrated chips and (b) machined surface (Reprinted with permission from Elsevier @ 2017)

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Fig. 19

X-ray diffraction patterns of Ti-6Al-4V alloy [31]: (a) the bulk material, (b) the secondary deformation zone of serrated chips at the cutting speed of 500 m/min, and (c) the machined surface at the cutting speed of 500 m/min (Reprinted with permission from Elsevier @ 2017)

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Fig. 20

Phase transformation of β-Ti to α-Ti and α″-Ti induced the stress variation in the cooling process of HSM Ti-6Al-4V: (a) the flow stress contour induced by phase transformation in the rapid cooling process and (b) the flow stress variation at different cutting speeds in the rapid cooling process

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Fig. 21

The relationship between the measured flow stress and the microstructural variations-induced hardening

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Fig. 22

Comparison between (a) predicted microhardness variation at the cutting speed of 200 m/min and (b) measured microhardness value in a shear band of serrated chips

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Fig. 23

Comparisons between the predicated hardness and the measured values at various cutting speed

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