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.

References

References
1.
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
.
2.
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
.
3.
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
.
4.
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
.
5.
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
.
6.
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
.
7.
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
.
8.
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
.
9.
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
.
10.
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
.
11.
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
.
12.
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
.
13.
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
.
14.
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
.
15.
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
.
16.
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
.
17.
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
.
18.
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
.
19.
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
.
20.
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
.
21.
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
.
22.
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
.
23.
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
.
24.
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
.
25.
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
.
26.
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
.
27.
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
.
28.
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
.
29.
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
.
30.
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
.
31.
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
.
32.
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
.
33.
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
.
34.
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
.
35.
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
.
36.
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
.
37.
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.
38.
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.
39.
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
.
40.
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
.
41.
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
.
42.
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
.
43.
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
.
44.
Yoo
,
M. H.
,
1981
, “
Slip, Twinning, and Fracture in Hexagonal Close-Packed Metals
,”
Metall. Mater. Trans. A
,
12A
(
3
), pp.
409
418
.
45.
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
.
46.
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
.
47.
Chaudhri
,
M. M.
,
1988
, “
Subsurface Strain Distribution Around Vickers Hardness Indentations in Annealed Polycrystalline Copper
,”
Acta Mater.
,
46
(
9
), pp.
3047
3056
.
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