本論文對生醫鈦合金材料Ti-12Mo-6Zr-2Fe(TMZF)進行材料性質分析。靜態方面以不同的熱處理製程與硬度分析探討TMZF析出物對物理性質的影響；動態分析則以分離式霍普金森桿撞擊試驗機(SHPB)，分別於25oC、450 oC與900 oC三種不同的溫度下進行高速撞擊，使材料內部產生極高應變速率之剪切變形。利用帽形試件(Hat-Shaped Specimen)外觀之幾何設計導引絕熱剪切帶之生成，並觀察其絕熱剪切變形行為。剪應變速率控制於3.4×104s-1、7.1×104s-1、1.05×105s-1，藉由觀察實驗所得之巨觀機械性質和微觀材料破壞機制，來了解在極高剪應變速率下的動態剪切特性及剪切帶微觀組織(OM、SEM)之變化，並探討不同剪應變速率與溫度對材料剪切變形行為之影響。
900oC實驗由於材料性質與選定實驗條件的關係，無法測得計算所需之剪切區寬度，因此本文之900oC剪切區寬度僅以推測值對材料趨勢加以討論，並非實際實驗結果。
實驗結果顯示，應變速率越大、環境溫度越低，會有越高的理論溫升量。塑流應力值隨應變速率上升而上升，實驗溫度為25oC、450oC時，應力在達到一極大值後便會因熱軟化效應開始下降。而實驗溫度為900oC時，環境溫度已使材料充分軟化，變形過程中應力呈現持續上升。較高之應變速率會有較高的溫度敏感性係數，溫度區間為450oC-900oC時，一開始的溫度敏感性係數值會較溫度區間為25 oC-450 oC時高。但隨著應變量的上升，溫度區間為450oC-900oC時的溫度敏感性係數會變得比較小。環境溫度越高，應變速率敏感性係數越高，熱活化體積大致上較高，活化能較高。實驗溫度為25 oC、900 oC時，高應變速率區間的溫升會使熱軟化明顯，應變速率敏感性係數反而較小，熱活化體積較高。450 oC時則由於應變速率提高會使硬化現象更明顯，而呈現相反的趨勢。
在微觀的方面，25 oC、450 oC的實驗條件皆可發現絕熱剪切帶、韌窩與節瘤的形貌。剪切帶寬度會隨著應變速率的上升而下降，剪切帶周遭常可發現裂痕的生成。韌窩為塑性變形常見的破壞型態，節瘤則是材料發生熔融後又快速冷卻的證明。在理論溫升量不高的條件中可觀察到節瘤，亦可說明非均勻變形過程的各處局部應變與局部溫升量差異甚大之現象。

Adiabatic shearing behaviors under extremely high shear loading and microstructural characteristics of Ti-12Mo-6Zr-2Fe (TMZF) with three different experimental temperatures are investigated under shear strain rates ranging from 3.4×104s−1 to 1.05×105s−1 using a compressive split-Hopkinson pressure bar (SHPB). The results indicate the mechanical properties of TMZF are sensitivity to strain rate and experimental temperature. Shear stress will rise first and then fall down under 25oC and 450oC, but it will keep rising under 900oC. As strain rate increases, the maximum values of shear stress and strain, theoretical rising temperature, temperature sensitivity as increase. Strain rate sensitivity would be greater within lower interval of strain rate under 25oC and 900oC but lower under 450oC, while thermal activation volume shows opposite trends in comparison to strain rate sensitivity. As experimental temperature is increased, the maximum values of shear stress and strain, theoretical rising temperature, strain rate sensitivity all decrease. Within higher interval of experimental temperatures, temperature sensitivity would have a greater value at first but goes lower than lower interval later. Thermal activation volume still shows opposite to strain rate sensitivity. Optical microscope (OM) observations and micro-hardness tests reveal that the width of adiabatic shear band (ASB) decreases as strain rate increases or experimental temperature decreases. Cracks and precipitations can be observed in the shearing regions. Scanning electron microscopy (SEM) observations show that dimple and knobby structures exist, suggesting ductile fracture and the evidence of melting of the material have occurred, respectively.

[1] M. A. Meyers, Dynamic Behavior of Materials. John Wiley & Sons, Inc., 605 Third Avenue, New York, NY 10158-0012., 1994.
[2] B. Hopkinson, “A Method of Measuring the Pressure Produced in the Detonation of High Explosives or by the Impact of Bullets,” Philos. Trans. R. Soc. A Math. Phys. Eng. Sci., vol. 213, no. 497–508, pp. 411–413, 2006.
[3] H. Kolsky, “An Investigation of the Mechanical Properties of Materials at very High Rates of Loading,” Proceeding Phys. Soc. Sect. B, pp. 676–700, 1949.
[4] B. M. Butcher and C. H.Karnes, “Strain-Rate Effects in Metals,” J. Appl. Phys., vol. 37, no. 1, pp. 402–411, 1966.
[5] F. E. Hauser, “Techniques for Measuring Stress-Strain Relations at High Strain Rates and Typical Results Presented,” Exp. Mech., pp. 395–402, 1966.
[6] D. J. Steinberg, S. G. Cochran, and M. W. Guinan, “A Constitutive Model for Metals Applicable at High-Strain Rate,” J. Appl. Phys., vol. 51, no. 3, pp. 1498–1504, 1980.
[7] C. Y. Chiem and J. Duffy, “Strain Rate History Effects and Observations of Dislocation Substructure in Aluminum Single Crystals Following Dynamic Deformation,” Mater. Sci. Eng., vol. 57, no. 2, pp. 233–247, 1983.
[8] Y. Li, C. Yang, H. Zhao, S. Qu, X. Li, and Y. Li, “New Developments of Ti-Based Alloys for Biomedical Applications,” Materials (Basel)., vol. 7, no. 3, pp. 1709–1729, 2014.
[9] J. Black, “The Education of the Biomaterialist: Report of a Survey, 1980-81,” J. Biomed. Mater. Res., vol. 16, no. 3, pp. 159–167, 1982.
[10] S. Bose and A. Bandyopadhyay, Characterization of Biomaterials. Elsevier, 2013.
[11] K. P. Andriano, Y. Tabata, Y. Ikada, and J. Heller, “In Vitro and In Vivo Comparison of Bulk and Surface Hydrolysis in Absorbable Polymer Scaffolds for Tissue Engineering,” J Biomed Mater Res (Appl Biomater), vol. 48, pp. 602–612, 1999.
[12] T. Yamamuro, T. Nakamura, H. Iida, K. Kawanabe, Y. Matsuda, K. Ido, J. Tamura and Y. Senaha, “Development of Bioactive Bone Cement and Its Clinical Applications,” Biomaterials, vol. 19, pp. 1479–1482, 1998.
[13] J. R. P. Jorge, V. A. Barao, J. A. Delben, L. P. Faverani, T. P. Queiroz and W. G. Assuncao, “Titanium in Dentistry: Historical Development , State of the Art and Future Perspectives,” J Indian Prosthodont Soc, vol. 13, no. June, pp. 71–77, 2013.
[14] M. Losertová, “Advanced Materials,” in Advanced Materials, First., VŠB – Technical Univesity of Ostrava, 2014, pp. 43–62.
[15] W. Kathy, “The Use of Titanium for Medical Applications in the USA,” Mater. Sci. Eng. A, vol. 213, pp. 134–137, 1996.
[16] M. Niinomi and M. Nakai, “Titanium-Based Biomaterials for Preventing Stress Shielding between Implant Devices and Bone,” vol. 2011, 2011.
[17] A. Choubey, R. Balasubramaniam, and B. Basu, “Effect of Replacement of V by Nb and Fe on the Electrochemical and Corrosion Behavior of Ti-6Al-4V in Simulated Physiological Environment,” J. Alloys Compd., vol. 381, no. 1–2, pp. 288–294, 2004.
[18] K. Bordji, J. Y. Jouzeau, D. Mainard, E. Payan, P. Netter, K. T. Rie, T. Stucky and M. Hage-Ali, “Cytocompatibility of Ti-6Al4V and Ti-5Al-2 . 5Fe Alloys According to Three Surface Treatments , Using Human Fibroblasts and Osteoblasts,” vol. 17, no. 9, pp. 929–940, 1996.
[19] M. T. Mohammed, “Beta Titanium Alloys: The Lowest Elastic Modulus for Biomedical Applications: A Review,” Mater. Metall. Eng., vol. 8, no. 8, pp. 822–827, 2014.
[20] T. Mctighe, D. Brazil, and W. Bruce, “Metallic Alloys in Total Hip Arthroplasty,” in The Hip: Preservation, Replacement, and Revision, 2015, pp. 1–12.
[21] A. Schuh, J. Bigoney, W. Hönle, G. Zeiler, U. Holzwarth, and R. Forst, “Second Generation (Low Modulus) Titanium Alloys in Total Hip Arthroplasty,” Materwiss. Werksttech., vol. 38, no. 12, pp. 1003–1007, 2007.
[22] L. Gracia, E. Ibarz, J. Cegonino, A. Lobo-Escolar, S. Gabarre, S. Puertolas, E. Lopez, J. Mateo and A. Herrera, “Simulation by Finite Elements of Bone Remodeling After Implantation of Femoral Stems,” Finite Elem. Anal. - From Biomed. Appl. to Ind. Dev., pp. 217–250, 2012.
[23] X. Liu, P. K. Chu, and C. Ding, “Surface Modification of Titanium, Titanium Alloys, and Related Materials for Biomedical Applications,” Mater. Sci. Eng. R Reports, vol. 47, no. 3–4, pp. 49–121, 2004.
[24] C. N. Elias, J. H. C. Lima, R. Valiev, and M. A. Meyers, “Biomedical Applications of Titanium and Its Alloys,” J. Biol. Mater. Sci., no. March, pp. 1–4, 2008.
[25] M. Niinomi, “Biologically and Mechanically Biocompatible Titanium Alloys,” Mater. Trans., vol. 49, no. 10, pp. 2170–2178, 2008.
[26] M. J. Donachie, Titanium - A Techinacal Guide, Second. 2000.
[27] G. Lütjering and J. C. Williams, Titanium, 2nd ed., vol. 274, no. 1–2. Springer-Verlag Berlin Heidelberg, 1998.
[28] R. Kolli and A. Devaraj, “A Review of Metastable Beta Titanium Alloys,” Metals (Basel)., vol. 8, no. 7, pp. 1–26, 2018.
[29] Q. V. Vu, “Recrystallisation in a Rapidly Annealed Low Cost β- Titanium Alloy,” 2012.
[30] M. Geetha, A. K. Singh, R. Asokamani, and A. K. Gogia, “Ti Based Biomaterials, the Ultimate Choice for Orthopaedic Implants - A Review,” Prog. Mater. Sci., vol. 54, no. 3, pp. 397–425, 2009.
[31] P. Laheurte, A. Eberhardt, and M. J. Philippe, “Influence of the Microstructure on the Pseudoelasticity of a Metastable Beta Titanium Alloy,” Mater. Sci. Eng. A, vol. 396, no. 1–2, pp. 223–230, 2005.
[32] I. Weiss and S. L. Semiatin, “Thermomechanical Processing of Beta Titanium Alloys - An Overview,” Mater. Sci. Eng. A, vol. 243, no. 1–2, pp. 46–65, 1998.
[33] 胡亮, 郭順, 孟慶坤, and 趙新青, “熱-機械處理對亞穩β鈦合金微觀組織和力學性能的影響,” Rare Met. Mater. Eng., vol. 44, no. 1, pp. 146–151, 2015.
[34] K. K. Wang, L. J. Gustavson, and J. H. Dumbleton, “Microstructure and Properties of a New Beta Titanium Alloy, Ti-12Mo-6Zr-2Fe, Developed for Surgical Implants,” Med. Appl. Titan. Its Alloy. Mater. Biol. Issues, ASTM STP 1272, pp. 76–87, 1996.
[35] J. I. Qazi and H. J. Rack, “Metastable Beta Titanium Alloys for Orthopedic Applications,” Adv. Eng. Mater., vol. 7, no. 11, pp. 993–998, 2005.
[36] S. Nag, R. Banerjee, J. Stechschulte, and H. L. Fraser, “Comparison of Microstructural Evolution in Ti-Mo-Zr-Fe and Ti-15Mo Biocompatible Alloys,” J. Mater. Sci. Mater. Med., vol. 16, no. 7, pp. 679–685, 2005.
[37] W. F. Ho, S. C. Wu, S. K. Hsu, Y. C. Li, and H. C. Hsu, “Effects of Molybdenum Content on the Structure and Mechanical Properties of as-cast Ti-10Zr-Based Alloys for Biomedical Applications,” Mater. Sci. Eng. C, vol. 32, no. 3, pp. 517–522, 2012.
[38] J. Málek, F. Hnilica, J. Vesely, B. Smola, K. Kolarik, J. Fojt, M. Vlach and V. Kodetova, “The Effect of Zr on the Microstructure and Properties of Ti-35Nb-XZr Alloy,” Mater. Sci. Eng. A, vol. 675, pp. 1–10, 2016.
[39] P. Mohan, A. B. Elshalakany, T. A. Osman, V. Amigo, and A. Mohamed, “Effect of Fe Content, Sintering Temperature and Powder Processing on the Microstructure, Fracture and Mechanical Behaviours of Ti-Mo-Zr-Fe Alloys,” J. Alloys Compd., vol. 729, pp. 1215–1225, 2017.
[40] W. Lee and C. Lin, “Plastic Deformation and Fracture Behaviour of Ti-6Al-4V Alloy Loaded with High Strain Rate under Various Temperatures,” Mater. Sci. Enginnering A, vol. 241, pp. 48–59, 1998.
[41] B. Dodd and Y. Bai, Adiabatic Shear Localization, First. 1992.
[42] K. Minnaar and M. Zhou, “An Analysis of the Dynamic Shear Failure Resistance of Structural Metals,” J. Mech. Phys. Solids, vol. 46, no. 10, pp. 2155–2170, 1998.
[43] X. Teng, T. Wierzbicki, and H. Couque, “On the Transition From Adiabatic Shear Banding to Fracture,” Mech. Mater., vol. 39, no. 2, pp. 107–125, 2007.
[44] H. Couque, “A Hydrodynamic Hat Specimen to Investigate Pressure and Strain Rate Dependence on Adiabatic Shear Band Formation,” J. Phys. IV, vol. 110, pp. 423–428, 2003.
[45] R. Clos, U. Schreppel, and P. Veit, “Temperature, Microstructure and Mechanical Response During Shear-Band Formation in Different Metallic Materials,” J. Phys. IV, vol. 110, pp. 111–116, 2003.
[46] V. Pushkov, A. Yurlov, A. Bol’shakov, A. Podurets, A. Kal’manov, and E. Koshatova, “Study of Adiabatic Localized Shear in Metals by Split Hopkinson Pressure Bar Method,” in EPJ Web of Conferences, 2011, vol. 10, p. 00029.
[47] U. Andrade, M. A. Meyers, K. S. Vecchio, and A. H. Chokshi, “Dynamic Recrystallization in High-Strain, High-Strain-Rate Plastic Deformation of Copper,” Acta Metall. Mater., vol. 42, no. 9, pp. 3183–3195, 1994.
[48] J. Peirs, P. Verleysen, J. Degrieck, and F. Coghe, “The Use of Hat-Shaped Specimens to Study the High Strain Rate Shear Behaviour of Ti-6Al-4V,” Int. J. Impact Eng., vol. 37, no. 6, pp. 703–714, 2010.
[49] S. Diego and L. Jolla, “Microstructure of High-Strain, High-Strain-Rate Deformed Tantalum,” Acta Metall., vol. 46, no. 4, pp. 1307–1325, 1998.
[50] M. A. Meyers, V. F. Nesterenko, J. C. LaSalvia, and Q. Xue, “Shear Localization in Dynamic Deformation of Materials: Microstructural Evolution and Self-Organization,” Mater. Sci. Eng. A, vol. 317, no. 1–2, pp. 204–225, 2001.
[51] Y. Yang, X. M. Li, X. L. Tong, Q. M. Zhang, and C. Y. Xu, “Effects of Microstructure on the Adiabatic Shearing Behaviors of Titanium Alloy,” Mater. Sci. Eng. A, vol. 528, no. 7–8, pp. 3130–3133, 2011.
[52] W. L. Richards, “Strain Gage Measurement Errors in the Transient Heating of Structural Components Strain Gage Measurement,” NASA Tech. Memo. 104274, 1993.
[53] K. Oi, “Transient Response of Bonded Strain Gages,” Exp. Mech., vol. 6, no. 9, pp. 463–469, 1966.
[54] L. W. Bickle, “The Response of Strain Gages to Longitudinally Sweeping Strain Pulses,” Exp. Mech., vol. 10, no. 8, pp. 333–337, 1970.
[55] G. Britain, P. Press, and D. Division, “An Experimental Study of the Formation Process of Adiabatic Shear Bands in a Structural Steel,” vol. 36, no. 3, pp. 251–283, 1988.
[56] B. Dodd and Y. Bai, Adiabatic Shear Localization, Second. Elsevier, 2012.
[57] J. A. Zukas, T. Nicholas, H. F. Swift, L. B. Greszczuk, and D. R. Curran, Impact Dynamics. John Wiley & Sons, 1982.
[58] D. Klahn, A. K. Mukherjee, and J. E. Dorn, “Strain-Rate Effects,” 1970.
[59] J. D. Campbell and W. G. Ferguson, “The Temperature and Strain-Rate Dependence of the Shear Strength of Mild Steel,” Philos. Mag., vol. 21, no. 169, pp. 63–82, 1970.
[60] G. Schoeck and B. Wielke, “Strain Rate Changes and Activation Volume,” Scr. Metall., vol. 10, pp. 771–774, 1976.
[61] J. C. Fisher, W. G. Johnston, R. Thomson, and J. T. Vreeland, “Dislocations and Mechanical Properties of Crystals,” pp. 5009–5010, 1956.
[62] A. Seeger, “The Generation of Lattice Defects by Moving Dislocations, and Its Application to the Temperature Dependence of the Flow-Stress of F.C.C. Crystals,” London, Edinburgh, Dublin Philos. Mag. J. Sci., vol. 46, no. 382, pp. 1194–1217, 1955.
[63] U. R. Andrade, M. A. Meyers, and A. H. Chokshi, “Constitutive Description of Work- and Shock-Hardened Copper,” Scr. Metall. Mater., vol. 30, no. 7, pp. 933–938, 1994.
[64] H. Conrad, “Thermally Activated Deformation of Metals,” Jom, vol. 16, no. 7, pp. 582–588, 1964.
[65] M. P. Victoria, C. K. H. Dharan, F. E. Hauser, and J. E. Dorn, “Dislocation Damping at High Strain Rates in Aluminum and Aluminum-Copper Alloy,” J. Appl. Phys., vol. 41, no. 2, pp. 674–677, 1970.
[66] J. D. Campbell, “Dynamic Plasticity: Macroscopic and Microscopic Aspects,” Mater. Sci. Eng., vol. 12, no. 1, pp. 3–21, 1973.
[67] S. L. Semiatin and G. D. Lahoti, “Deformation and Unstable Flow in Hot Forging of Ti-6AI-2Sn-4Zr-2Mo-0.1Si,” vol. l, no. October, 1981.
[68] D. S. Kim, S. Nemat-Nasser, J. B. Isaacs, and D. Lischer, “Adiabatic Shearband in WHA in High-Strain-Rate Compression,” Mech. Mater., vol. 28, no. 1–4, pp. 227–236, 1998.
[69] D.-K. Kim, S. Lee, and W. Hyung Baek, “Microstructural Study of Adiabatic Shear Bands Formed by High-Speed Impact in a Tungsten Heavy Alloy Penetrator,” Mater. Sci. Eng. A, vol. 249, no. 1–2, pp. 197–205, 1998.
[70] C. Zener and J. H. Hollomon, “Effect of Strain Rate Upon Plastic Flow of Steel,” J. Appl. Phys., vol. 15, no. 1, pp. 22–32, 1944.
[71] S. P. Timothy, “The Structure of Adiabatic Shear Bands in Metals: A Critical Review,” Acta Metall., vol. 35, no. 2, pp. 301–306, 1987.
[72] R. C. Batra and C. H. Kim, “Effect of Thermal Conductivity on the Initiation, Growth and Bandwidth of Adiabatic Shear Bands,” Int. J. Eng. Sci., vol. 29, no. 8, pp. 949–960, 1991.
[73] A. K. Zurek, “The Study of Adiabatic Shear Band Instability in a Pearlitic 4340 Steel Using a Dynamic Punch Test,” Metall. Mater. Trans. A, vol. 25, no. 11, pp. 2483–2489, 1994.
[74] Y. B. Xu, Y. L. Bai, Q. Xue, and L. T. Shen, “Formation, Microstructure and Development of the Localized Shear Deformation in Low-Carbon Steels,” Acta Mater., vol. 44, no. 5, pp. 1917–1926, 1996.
[75] B. Dodd and Y. Bai, “Width of Adiabatic Shear Bands,” Mater. Sci. Technol., vol. 1, no. 1, pp. 38–40, 2014.
[76] Y. Chen, M. A. Meyers, and V. F. Nesterenko, “Spontaneous and Forced Shear Localization in High-Strain-Rate Deformation of Tantalum,” Mater. Sci. Eng. A, vol. 268, pp. 70–82, 1999.
[77] E. S. Dzidowski and W. Cisek, “New Development of Shear Fracture Research,” Mater. Process. Technol., vol. 106, pp. 267–272, 2000.
[78] J. H. Giovanola, “Adiabatic Shear Banding under Pure Shear Loading Part II: Fractographic and Metallographic Observations,” Mech. Mater., vol. 7, pp. 73–87, 1988.
[79] K. Cho, Y. C. Chi, and J. Duffy, “Microscopic Observations of Adiabatic Shear Bands in Three Different Steels,” Metall. Trans. A, vol. 21, no. 5, pp. 1161–1175, 1990.
[80] H. Kobayashi and B. Dodd, “A Numerical Analysis for The Formation of Adiabatic Shear Bands Including Void Nucleation and Growth,” Int. J. Impact Engng, vol. 8, no. 1, pp. 1–13, 1989.
[81] M. Zhou, A. Needleman, and R. J. Clifton, “Finite Element Simulations of Shear Localization in Plate Impact,” J. Mech. Phys. Solids, vol. 42, no. 3, pp. 423–458, 1994.
[82] E. El-Magd, “Mechanical Properties at High Strain Rates,” Le J. Phys. IV, vol. 04, no. C8, pp. C8-149-C8-170, 1994.
[83] T. W. Wright and J. W. Walter, “On Stress Collapse in Adiabatic Shear Bands,” J. Mech. Phys. Solids, vol. 35, no. 6, pp. 701–720, 1987.
[84] W. Lee and C. Liu, “Comparison of Dynamic Compressive Flow Behavior of Mild and Medium Steels over Wide Temperature Range,” Metall. Mater. Trans. A, vol. 36, no. November, 2005.
[85] J. A. C. Ambrosio, Crashworthiness. Springer-Verlag Wien New York, 2001.
[86] J. Gao, Y. Huang, D. Guan, A. J. Knowles, L. Ma, D. Dye, W. M. Rainforth, “Deformation Mechanisms in a Metastable Beta Titanium Twinning Induced Plasticity Alloy with High Yield Strength and High Strain Hardening Rate,” Acta Mater., vol. 152, pp. 301–314, 2018.