β型钛合金高温粘塑性本构建模及数值计算
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摘要
钛合金由于常温具有强烈的回弹倾向,因此常采用温间压力成形进行成形处理,但是许多钛合金在β相变点以上的应力应变曲线表现出明显的屈服点现象、急剧的屈服应力下降、应变软化以及强烈的应变速率敏感性。目前仍未有成熟的本构模型能够准确描述这一类特殊的粘塑性变形特征,因此无法对温间压力成形进行准确的模拟。
     本文对β型钛合金Ti-20V-4Al-1Sn在700℃、750℃以及800℃三种温度下的单轴应力应变曲线进行了测量,对Ti-20V-4Al-1Sn在上述温度区间内不同应变速率下不同应变阶段的变形微观组织进行系统观察,分析温度、应变速率以及塑性应变对材料微观组织演化的影响。力学实验结果表明,钛合金Ti-20V-4Al-1Sn在上述温度区间内的应力应变曲线具有明显的屈服点现象、急剧的屈服应力下降、应变软化以及强烈的应变速率敏感性。微观组织分析表明,屈服点以及屈服应力下降阶段伴随着晶界处位错密度的急剧变化,在大应变阶段,动态回复是流动软化的主要原因。
     基于Johnston-Gilman可动位错密度理论,本文首次推导出适用于钛合金高温粘塑性变形的本构方程,对钛合金在β相变点以上的温度区间内表现的屈服点现象、屈服点下降、流动软化以及应变速率敏感性进行建模。并采用基于多点近似拟合法的序列规划最优化方法对该粘塑性本构模型的各材料参数进行了拟合。结果表明,该本构模型能够准确的描述屈服点现象、屈服阶段的应力下降、大应变区域的流动软化以及应变速率敏感性。基于内部变量理论的本构方程构造使得该模型可以推广到其他牌号的钛合金以及表现出屈服点下降的其他材料如软钢、铝合金甚至硅晶体等。
     首次基于变形的亚弹性分解理论提出大变形框架下的本构方程,利用返回图算法原理首次提出适用于屈服点现象的本构方程隐式化求解算法,推导出适用于隐式求解的单元切线刚度矩阵。最终将上述模型利用商用有限元软件MSC.MARC的子程序HYPELA2编程实现,并进行了单轴拉伸以及V型弯曲过程的计算。计算结果表明,即使在复杂的接触条件以及较大时间增量步下,有限元分析同样可以达到优良的收敛率,并准确的再现高温屈服点下降现象。
Many high temperature mechanical tests ofβtitanium alloys show a common feature that the stress-strain curves exhibit a sharp initial peak stress followed by constant flow stress or flow softening. In this paper, high temperature deformation behavior of beta titanium alloy Ti-20V-4Al-1Sn sheet is studied by performing uniaxial tension experiments at three different strain rates at high temperatures of 700°C, 750°C and 800°C. The stress-strain curves at all temperature cases show strain rate sensitivity, yield point phenomena and continuous flow softening patterns. Microstructures of deformed specimens at several representative deformation stages and different strain rates are studied using optical microscope. Dynamic recovery does not occur at the early stage of deformation including yield-point and the subsequent yield drop regime, but it is activated at large deformation stage, where it is affected by strain rate and strain.
     As a first approach, a viscoplastic constitutive model based on the assumption of rapid dislocation multiplication is proposed to describe such high temperature yield-point phenomena. In this modeling, the softening effect due to dynamic recovery is also considered. The stress-strain responses predicted by the constitutive model well capture the yield-point phenomena, strain rate sensitivity and subsequent continuous flow softening behavior of the beta titanium alloy.
     The constitutive model is further implemented into commercial FE code by using implicit return mapping algorithm. The numerical implementation is constructed in a corotational frame under hypoelastic hypothesis to describe large deformation behaviors. The tangent matrix is also deduced in this paper to make the numerical calculation giving excellent convergence and stable results. The FE simulation results fit well with analytical calculation even at large time step. The generality of the model and the implicit algorithm makes it possible to extend the theory to other titanium alloys and the materials that have yield-point phenomena.
引文
1 I. Weiss, S. L. Semiatin. Thermomechanical Processing of Beta titanium Alloys-an Overview. Materials Science And Engineering A. 1998, 243(1): 46~65
    2 H. J. McQueen. Initiating nucleation of dynamic recrystallization, primarily in polycrystals. Materials Science and Engineering. 1988, (101), 149~160
    3 Y. Combres, B. Champin. in: D. Eylon, R.R. Boyer, D.A.Koss (eds.), Beta Titanium Alloys in the 1990s, TMS, PA, (1993) Warrendale: 27~38
    4 G. Kuhlman. Sixth World Conference on Titanium, Societe Francaise de Metallurgie, 1988, Les Ulis Cedx, France: 1269~1275
    5 R. Srinivasan and I. Weiss. Beta Titanium Alloys in the 1990s, TMS, PA (1993) Warrendale: 283~289
    6 F. Motheillet, D. Dajno, N. Come, E. Gautier, and A. Simon. Titanium '92: Science and technology, TMS, PA (1993) Warrendale: 1347~1360
    7 I. Weiss, S. L. Semiatin. Thermomechanical processing of alpha titanium alloys-an overview. Materials Science and Engineering A, 1999, 263(2): 243~256
    8 C. Schuh, D. C. Dunand. An Overview of Power-law Creep in Polycrystallineβ-titanium. Scripta Materialia. 2001,45(12): 1415~1421
    9 D. H. Shin, I. Kim, J. Kim, Y. S. Kim, S. L. Semiatin. Microstructure Development During Equal-channel Angular Pressing of Titanium. Acta Materialia. 2003, 51(4): 983~996
    10 M. E. Kassner, S. Nemat-Nasser, Z. G. Suo, G. Bao, J. C. Barbour, L. C. Brinson, H. Espinosa, H. J. Gao, S. Granick, P. Gumbsch, K. S. Kim, W. Knauss, L. Kubin, J. Langer, B. C. Larson, L. Mahadevan, A. Majumdar, S. Torquato, F. van Swol. New Directions in Mechanics. Mechanics of Materials. 2005, 37(2): 231~259
    11 D. A. S. Macdougall, J. Harding. A Constitutive Relation and Failure Criterion for Ti-6Al-4V Alloy at Impact Rates of Strain. Journal of the Mechanics and Physics of Solids. 1999, 47(5): 1157~1185
    12 A. A. Salem, S. R. Kalidindi, R. D. Doherty. Strain Hardening of Titanium:Role of Deformation Twinning. Acta Materialia, 2003, 51(14): 4225~4237
    13 A. A. Salem, S. R. Kalidindi, S. L. Semiatin. Strain Hardening due to Deformation Twinning inα-titanium: Constitutive Relations and Crystal-Plasticity Modeling. Acta Materialia, 2005, 53(12): 3495~3502
    14 G. R. Johnson, W. H. Cook. Fracture Characteristics of Three Metals Subjected to Various Strains, Strain rates, Temperatures and Pressures. Engineering Fracture Mechanics. 1985, 21(1): 31~48
    15 Rolf Sandstr?m, Inga Lindgren. The Combined Influence of Recrystallization and Recovery on Stress-strain Curves in Aluminium. 1981, 17(3): 217~228
    16 J-P.A Immarigeon, J.J Jonas. Flow Stress and Substructural Change During the Transient Deformation of Armco Iron and Silicon Steel. Acta Metallurgica. 1971, 19(10): 1053~1061
    17 L. Briottet, A. Ambard, D. Guichard. Ti-6Al-4V Plastic Deformation at Low Temperatures: a FEM Analysis Beyond the Onset of Instability. Modelling and Simulation in Materials Science and Engineering. 2001, 9(4): 259~277
    18 G. Z. Voyiadjis, R. K. Abu Al-Rub. Thermodynamic Based Model for the Evolution Equation of the Backstress in Cyclic Plasticity. International Journal of Plasticity. 2003, 19(12): 2121~2147
    19 A. Zolochevsky, G. Z. Voyiadjis. Theory of Creep Deformation with Kinematic Hardening for Materials with Different Properties in Tension and Compression. International Journal of Plasticity. 2005, 21(3): 435~462
    20 G. Z. Voyiadjis. Degradation of Elastic Modulus in Elastoplastic Coupling with Finite Strains. International Journal of Plasticity. 1988, 4(4): 335~353
    21 A. Cottrell. Theory of Dislocations. Progress in Metal Physics. 1953, (4): 205~264
    22 T. Neeraj, D. H. Hou, G. S. Daehn, M. J. Mills. Phenomenological and Microstructural Analysis of Room Temperature Creep in Titanium Alloys. Acta Materialia, 2000, 48(6): 1225~1238
    23 R. Dempers, K. Nikbin, G. A. Webster. Creep And Fracture Of Engineering Materials And Structures, 2000, (171-1): 153~163
    24 D. J. Selentano, J. L. Chaboche. Experimental and Numerical Characterization of Samage Evolution in Steels. International Journal of Plasticity. 2007, 23(10): 1739~1762
    25 J. L. Chaboche, O. Jung. Application of a Kinematic Hardening Viscoplasticity Model with Thresholds to the Residual Stress Relaxation. International Journal of Plasticity. 1997, 13(10): 785~807
    26 J. L. Chaboche. On Some Modifications of Kinematic Hardening to Improve the Description of Ratchetting Effects. International Journal of Plasticity. 1991, 7(7): 661~678
    27 J. L. Chaboche. Time-independent Constitutive Theories for Cyclic Plasticity. International Journal of Plasticity. 1986, 2(2): 149~188
    28 J. L. Chaboche. A Review of Some Plasticity and Viscoplasticity Constitutive Theories. International Journal of Plasticity. 2008, 24(10): 1642~1693
    29 A. D. Freed, K. P. Walker, and M. J. Verrilli. Extending the Theory of Creep to Viscoplasticity. Journal of Pressure Vessel Technology-Transactions of the ASME. 1994, (116): 67~75
    30 A. D. Freed, J. L. Chaboche, K. P. Walker. A Viscoplastic Theory with Thermodynamic Considerations. Acta Mechanica, 1991, (90): 155~174
    31 A. D. Freed and K. P. Walker, Viscoplastic Model Development with an Eye toward Characterization. Journal of Engineering Materials and Technology-Transactions of the ASME, 1995, (117): 8~13
    32 S. V. Raj, A. D. Freed. A Phenomenological Description of Primary Creep in Class M Materials. Materials Science and Engineering A. 2000, 283(1): 196~202
    33 A. D. Freed and K. P. Walker. Viscoplasticity with Creep and Plasticity Bounds. International Journal of Plasticity. 1993, 9(2): 213~242
    34 K. Hashiguchi. Generalized Plastic Flow Rule. International Journal of Plasticity. 2005, 21(2): 321~351
    35 F. Yoshida, T. Uemori, and K. Fujiwara. Elastic-plastic Behavior of Steel Sheets under In-plane Cyclic Tension-compression at Large Strain. International Journal of Plasticity. 2002, 18(5): 633~659
    36 F. Yoshida, T. Uemori. A Model of Large-strain Cyclic Plasticity Describing the Bauschinger Effect and Workhardening Stagnation. International Journal of Plasticity. 2002, 18(5): 661~686
    37 F. Yoshida, T. Uemori, Engineering Plasticity From Macroscale To NanoscalePts 1 And 2. 2003,233-2: 47~60
    38 F. Yoshida, M. Urabe, R. Hino, V. V. Toropov. Inverse Approach to Identification of Material Parameters of Cyclic Elasto-plasticity for Component Layers of a Bimetallic Sheet. International Journal of Plasticity. 2003, 19(12): 2149~2170
    39 M. Wagenhofer, M. Erickson-Natishan, R. W. Armstrong, F. J. Zerilli. Influences of Strain Rate and Grain Size on Yield and Serrated Flow in Commercial Al-Mg Alloy 5086. Scripta Materialia. 1999, 41(11): 1177~1184
    40 F. J. Zerilli, R. W. Armstrong. A Constitutive Equation for the Dynamic Deformation Behavior of Polymers. Journal of Materials Science. 2007, 42(12): 4562~4574
    41 F. J. Zerilli, R. W. Armstrong. Dislocation Mechanics Based Analysis of Material Dynamics Behavior. Journal De Physique Iv. 1997,(7c3):637~642
    42 R. W. Armstrong, F. J. Zerilli. Dislocation Mechanics Aspects of Plastic Instability and Shear Banding. Mechanics of Materials. 1994, 17(2-3):319~327
    43 E. Krempl, F. Khan. Rate (time)-dependent Deformation Behavior: an Overview of Some Properties of Metals and Solid Polymers. International Journal of Plasticity. 2003, 19(7): 1069~1095
    44 A.S. Khan, Y. Sung Suh, R. Kazmi. Quasi-static and Dynamic Loading Responses and Constitutive Modeling of Titanium Alloys. International Journal of Plasticity. 2004, 20(12): 2233~2248
    45 R.Liang, A.S. Khan. A Critical Review of Experimental Results and Constitutive Models for BCC and FCC Metals over a Wide Range of Strain Rates and Temperatures. International Journal of Plasticity. 1999, 15(9): 963~980
    46刘孝敏.工程材料的微细观结构和力学性能.中国科学技术大学出版社. 2003:30~35
    47 J. J. Chiu, Dislocation Based Finite Element Modelling of Elasto-plastic Material Deformation, Master Thesis, UCLA, 2004: 45~60
    48 H. Conard In: G. Thames and J. Washburn, Editors, Electron Microscopy and Strength of Crystals, Interscience, New York 1961:299~300.
    49 E. Orowan, Symposium on International Stresses, Inst. of Metal, London 1947: 451~463
    50 S. Mader H Rebstock A. Seeger, J. Diehl. Work-hardening and worksoftening of face-centred cubic metal crystals. Philosophical Magazine, 1957, (2):323~331
    51 P. Haasen A. S. Argon. A New Mechanism of Work Hardening in the Late Stages of Large Strain Plastic Flow in FCC and Diamond Cubic Crystals. Acta Metallurgica. 1993, (41):3289~3306
    52 Z. S. Basinski. Thermally Activated Glide in Face-Centred Cubic Metals and Its Application to the Theory of Strain Hardening. Philosophical Magazine. 1959, 4:393~402
    53 Y. Bergstrom. A Dislocation Model for the Stress-strain Behavior of Polycrystallineα-Fe with Special Emphasis on the Variation of the Densities of Mobile and Immobile Dislocations. Materials Science and Engineering. 1970, (5):193~200
    54 A. H. Cottrell. Theory of Dislocations. Progress in Metal physics. 1953,(4): 205~264
    55 A. H. Cottrell. Dislocations and Plastic Flow in Crystals. Clarendon Press, Oxford: 1953, 85~95
    56 J. Moteff, D J. Michel, A. J. Lovell. Substructure of Type 316 Stainless Steel Deformed in Slow Tension at Temperatures Between 21°and 816°C. Acta Metallurgica, 1973, (21):1269~1277
    57 U. Essmann and H. Mughrabi. Annihilation of Dislocations during Tensile and Cyclic Deformation and Limits of Dislocation Densities. Philosophical Magazine A, 1979, (40): 731~756
    58 U.F. Kocks H. Mecking. Physics and Phenomenology of Strain Hardening: the FCC Case. Progress in Materials Science, 2003, (48): 171~273
    59 U.F. Kocks H. Mecking. Kinetics of Flow and Strain-hardening. Acta Metallurgica, 1981, (29):1865~1875
    60 U.F. Kocks. Statistical Theory of Flow Stress and Work-hardening. Philosophical Magazine, 1966, (13): 541~560
    61 U.F. Kocks, A.S. Argon, M.F. Ashby , Thermodynamics and Kinetics of Slip. Progress in Materials Science. 1975,(19):1~291
    62 U. F. Kocks. Polyslip in Single Crystals. Acta Metallurgica, 1960, (8): 345~352
    63 U.F. Kocks, S.R. Chen. On the Two Distinct Effects of Thermal Activation onPlasticity. Physics Statistical Solutions, 1992, (131A): 403~414
    64 U.F. Kocks, T. Hasegawa, R.O. Scattergood, On the Origin of Cell Walls and of Lattice Misorientations during Deformation. Scripta Metallurgica, 1980, (14): 449~454
    65 U. F. Kocks. Laws for Work Hardening and Low Temperature Creep. Journal of Engineering Materials and Technology, Transactions of the ASME, 1976, (98): 76~85
    66 A. J. Beaudoin, H. Mecking, U. F. Kocks. Development of Localized Orientation Gradients in FCC Polycrystals. Philosophical Magazine. 1996, (A73): 1503~1517
    67 H. Mecking, B. Nicklas, N. Zarubova, U.F. Kocks. A“Universal”Temperature Scale for Plastic Flow. Acta Metallurgica. 1986,(34): 527~535
    68 K. Morii, H. Mecking, Y. Nakayama. Development of Shear Bands in f.c.c. Single Crystals. Acta Metallurgica. 1985, (33): 379~386
    69 Y. Estrin, H. Mecking. A Unified Phenomenological Desription of Work Hardening and Creep Based on One-parametert Models. Acta Metallurgica. 1984, (32): 57~70
    70 Y. Estrin, L.S. Tóth, A. Molinary, I. Bréchet. A Dislocation-based Model for All Hardening Stages in Large Strain Deformation. Acta Materialia, 1998, (46): 5509~5522
    71 Y. Estrin. Dislocation Theory Based Constitutive Modelling: Foundations and Applications. Materials Processing Technology. 1998, (80-81):33~39
    72 G. Gottstein, A.S. Argon. Dislocation Theory of Steady State Deformation and Its Approach in Creep and Dynamic Tests. Acta Metallurgica. 1987, (35): 1261~1271
    73 D. Ponge, G. Gottstein. Necklace Formation during Dynamic Recrystallization: Mechanisms and Impact on Flow Behavior. Acta materialia. 1998, (46): 69~80
    74 R.E. Cook, G. Gottstein, U.F. Kocks. Recovery in Deformed Cu and Ni Single Crystals. Journal of Materials Science 1983, (18): 2650~2664
    75 R. Luce, M. Wolske, R. Kopp, F. Roters, G. Gottstein. Application of a Dislocation Model for FE-process Simulation. Computational Materials Science. 2001, (21): 1~8
    76 R. Lagneborg. Bypassing of Dislocations Past Particles by a Climb Mechanism.Scripta Metallurgica. 1973, (7): 605~613
    77 F. Prinz, H. Kirchner, G Schoeck. Dislocation Core Energies in the Peierls Model. Philosophical Magazine A. 1978, (38): 321~332
    78 H. Mughrabi, Dislocation Wall and Cell Structures and Long-range Internal Stresses in Deformed Metal Crystals. Acta Metallurgica.1983, (31):1367~1379
    79 U. Essmann, H. Mughrabi. Annihilation of Dislocations During Tensile and Cyclic Deformation and Limits of Dislocation Densities. Philosophical Magazine A. 1979, (40): 731~756
    80 W. Blum, B. Reppich. On the Stress Dependence of the Stationary Deformation Rate. Acta Metallurgica, 1969, (17): 959~966
    81 F. R. N. Nabarro. Steady-state Diffusional Creep. Philosophical Magazine. 1967, (16): 231~237
    82 F. R. N. Nabarro. The Theory of Solution Hardening. Philosophical Magazine. 1977, (35): 613~622
    83 J. H. Gittus. Multiaxial Mechanical Equation of States for a Workhardening Recovery Model of Dislocation Creep. Philosophical Magazine. 1972,(25): 1233~1241
    84 J. H. Gittus. Theoretical Value of the Ratio (k) of Cell Diameter to Dislocation Spacing for a Material Undergoing Dislocation-creep. Philosophical Magazine, 1977, (34): 293~307
    85 J. H. Gittus. Theoretical Ralationship Between Free Energy and Dislocation Cell Diameter During Creep. Philosophical Magazine. 1979, (39): 829~841
    86 J. Gittus. The Mechanical Equation of States: Dislocation Creep due to Stresses Varying in Magnitude and Direction. Philosophical Magazine. 1971, (43): 1423~1440
    87 J. Gittus. Theoretical Equation for Steady-state Dislocation Creep. Philosophical Magazine. 1976, (34): 401~411
    88 F. Yoshida. A Constitutive Model of Cyclic Plasticity. International Journal of Plasticity. 2000, (16): 359~380
    89 F. Yoshida, Y. Kaneda, S. Yamamoto. A Plasticity Model Describing Yield-point Phenomena of Steels and Its Application to FE Simulation of Temper Rolling. International Journal of Plasticity. 2008, (24): 1792~1818
    90 H. B. Sun, F. Yoshida, M. Ohmori, X. Ma. Effect of Strain Rate on Lüders Band Propagating Velocity and Lüders Strain for Annealed Mild Steel under Uniaxial Tension. Materials Letters. 2003, (57): 4535~4539
    91 H. B. Sun, F. Yoshida, M. Ohmori, X. Ma. Finite Element Simulation on the Propagation of Luders Band and Effect of Stress Concentration. Materials Letters. 2003, (57): 3206~3210
    92 A. H. Cottrell, B. A. Bilby. Dislocation Theory of Yielding and Strain Ageing of Iron. Proceedings of the Physical Society, Section A. 1949,(62): 49~62
    93 G. W. Ardley, A. H. Cottrell. Yield Points in Brass Crystals. Proceedings of the Royal Society of London. Series A. 1953, (219): 328~341
    94 B. A. Bilby, A. H. Cottrell, K. H. Swinden. The Spread of Plastic Yield from a Notch. Proceedings of the Royal Society of London. Series A. 1963, (272): 304~314
    95 A. H. Cottrell, R. J. Stokes. Effects of Temperature on the Plastic Properties of Aluminium Crystals. Proceedings of the Royal Society of London. Series A. 1955, (233):17~34
    96 J. J. Gilman. Dislocation Sources in Crystals. Journal of Applied Physics. 1959,(30): 1584~1594
    97 G. T. Hahn. A Model for Yielding with Special Reference to the Yield-point Phenomena of Iron and Related BCC Metals. Acta Metallugica. 1962, (10): 727~738
    98 W. G. Johnston, J. J. Gilman. Dislocation Velocities, Dislocation Densities, and Plastic Flow in Lithium Fluoride Crystals. Journal of Applied Physics. 1959, (30): 129~143
    99 I. Philippart, H. J. Rack. High Temperature, High Strain Deformation Behavior of Ti–6.8Mo–4.5Fe–1.5Al. Materials Science and Engineering A. 1998, (254): 253~267
    100 B. Han, Z. Xu. Microstructural Evolution of Fe-32%Ni Alloy During Large Strain Multi Axial Forging. Matrials Science and Engineering: A, 2007, 447(1-2):119~124
    101 L. Fratini, G. Buffa. CDRX Modeling in Friction Stir Welding of Aluminum Alloys. International Journal of Machine Tools and Manufacture. 2005, 45(10): 1188~1194
    102 T. A. Mason, B. L. Adams. The Application of Orientation Imaging Microscopy. Journal of inMetal and Material. 1994, 46(10): 43~45
    103 M. R. Bache, W. J. Evans, H. M Davis. Electron Back Scattered Diffraction (EBSD) Analysis of Quasi-cleavage and Aydrogen Induced Fractures under Cyclic andDwell Loading in Titanium Alloys. Journal of Materials Science. 1997, 32(13): 3435~3442
    104 M.R. Barnett, Z. Keshavarz, A.G. Beer, D. Atwell. Influence of Grain Size on the Compressive Deformation of Wrought Mg–3Al–1Zn. Acta Materialia. 2004, 52(17): 5093~5103
    105 S. R. Agnew, M. H. Yooa, C. N. Tomé. Application of Texture Simulation to Understanding Mechanical Behavior of Mg and Solid Solution Alloys Containing Li or Y. Acta Materialia. 2001, 49(20): 4277~4289
    106 D. Jorge-Badiola, A. Iza-Mendia, I. Gutiérrez. Study by EBSD of the Development of th Substructure in a Hot Deformed 304 Stainless Steel. Materials Science and Engineering A. 2005, 394(1-2): 445~454
    107 F. Yin, T. Hanamura, T. Inoue, K. Nagai. Fiber Texture and Substructural Features in the Caliber-rolled Low-carbon Steels. Metallurgical and Materials Transactions A. 2004, 35(2): 665~677
    108王昀.オーステナイト系ステンレス鋼の塑性変形および初期疲労損傷に関する微視的研究.名古屋大学博士论文. 2007: 33~35

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