本研究目的是研究新開發的Ti-7.5Mo合金其鑄造製程所得之疲勞行為，並選用目前商業用純鈦、Ti-6Al-4V與Ti-13Nb-13Zr合金作為實驗對照組，實驗結果顯示，鑄造純鈦的結構為鋸齒、不規則狀的板狀外觀，屬hcp的α相；鑄造Ti-6Al-4V及Ti-13Nb-13Zr合金結構為細針狀麻田散外觀，主要的相是hcp的α′相；鑄造Ti-7.5Mo合金結構則為細針狀麻田散外觀，屬介穩的α〞相。在本實驗的四種材料中，Ti-6Al-4V合金有最高的降伏強度、拉伸強度及拉伸模數，最低的延伸率。相較於純鈦，其他三種鈦合金皆有明顯較高的強度（YS及UTS）及較低的延伸率。相較於Ti-13Nb-13Zr合金，Ti-7.5Mo合金有相當的降伏強度、稍高的拉伸強度及稍低的延伸率。相較於Ti-13Nb-13Zr及Ti-7.5Mo合金，純鈦及Ti-6Al-4V合金有較高的抗應力控制型疲勞行為。在本實驗的四種材料中，以Ti-7.5Mo合金的抗應變控制型疲勞表現最好。四種材料的疲勞破損表面大致可以分成三個典型的部分：疲勞裂縫起始區、疲勞裂縫成長區及最後超荷重區。疲勞裂縫幾乎都起源於鑄造產生的表面/次表面孔洞。在疲勞裂縫成長區會有河流狀模式之裂縫破損成像。最後超荷重區域是典型的韌窩結構。影響這四種鑄造材料高週期疲勞性質的三種最主要因素為，鑄造引發的表面/次表面孔洞、孔洞的尺寸與位置、以及材料原本固有性質。
　　在牙科鑄造應用方面，包埋鑄造的Ti-7.5Mo合金其晶體結構皆主要為α〞相，但有少量的β相殘留。Ti-7.5Mo合金在三種模溫製程（300℃，150℃，室溫）會有相當比例的試片會預先斷裂，模溫越高，預先斷裂比例越高。除了純鈦以外，大部分β相鈦合金試片，相對於α〞/β及α′相類型之鈦合金，有較佳的抗彎曲破裂行為，其中又以Ti-15Mo-1Bi合金最為明顯。
　　更進一步研究有關純鈦、Ti-6Al-7Nb及Ti-15Mo-1Bi合金在包埋鑄造製程的鑄造性、機械性質、撓曲疲勞行為之比較，由實驗結果顯示，此三種材料的平均鑄造長度並無明顯統計上的差異，但Ti-6Al-7Nb合金的平均鑄造長度些微低於純鈦及Ti-15Mo-1Bi合金。鑄造純鈦結構為鋸齒、不規則狀的板狀外觀，屬hcp的α相；鑄造Ti-6Al-7Nb結構為細針狀麻田散外觀，屬hcp的α′相；鑄造Ti-15Mo-1Bi結構則為等軸外觀，屬介穩的β相。這三種材料的表面硬化層厚度相近。表面微硬度以Ti-15Mo-1Bi合金最高，而純鈦則最低。Ti-15Mo-1Bi及Ti-6Al-7Nb合金的體硬度相近，並且都遠大於純鈦。Ti-15Mo-1Bi及Ti-6Al-7Nb合金的彎曲強度相近，並且遠大於純鈦。而Ti-15Mo-1Bi合金的彎曲模數明顯低於純鈦及Ti-6Al-7Nb合金。Ti-15Mo-1Bi合金的彈性回復角則遠大於純鈦及Ti-6Al-7Nb合金。相較於Ti-6Al-7Nb合金，Ti-15Mo-1Bi合金有相近的UTS，但有明顯較高的YS、延伸率以及明顯較低的拉伸模數。固定撓曲疲勞表現，以Ti-15Mo-1Bi合金最好，而純鈦則最差。

　The purpose of the present study is to compare the high-cycle fatigue behavior of newly-developed as-cast Ti-7.5Mo alloy with that of c.p. Ti, Ti-13Nb-13Zr and Ti-6Al-4V alloys in their as-cast state. Experimental results indicate that the as-cast lath-type c.p. Ti has an α phase with hcp crystal structure. The cast Ti-6Al-4V and Ti-13Nb-13Zr alloys are dominated by a hexagonal α′ phase with an acicular martensitic morphology. The cast Ti-7.5Mo alloy is comprised primarily of a metastable α˝ phase also with a fine, acicular martensitic morphology. Among all investigated materials Ti-6Al-4V exhibits the highest YS, UTS and tensile modulus with the smallest elongation. All three Ti alloys demonstrate significantly higher strength and lower elongation values than c.p. Ti. Compared to Ti-13Nb-13Zr, Ti-7.5Mo has a little higher UTS, comparable YS, and a little lower elongation. Ti-6Al-4V and c.p. Ti have higher stress-controlled fatigue resistance but lower strain-controlled fatigue resistance than Ti-7.5Mo and Ti-13Nb-13Zr. Among four materials Ti-7.5Mo demonstrates the best strain-controlled fatigue performance. The fracture surfaces of the present materials are comprised of three morphologically distinct zones: crack initiation zone, crack propagation zone, and the final-stage overload zone. The fatigue cracks almost always initiate from casting-induced surface/subsurface pores. A river pattern is observed in the propagation zone. In the overload zone dimples are typically observed. Three factors most significantly affecting the fatigue performance of the present materials are the presence of the casting-induced surface/subsurface pores; the location of the pores; and the inherent mechanical properties of the materials.
　In dental investment casting procedure， the as-cast Ti-7.5Mo alloy has an α〞phase with the high-temperature β-phase barely visible. The premature failure was found during bending Ti-7.5Mo alloy in three different mold temperature casting procedures (300℃, 150℃, room temperature). The premature failure percentage increases by mold temperature. Bending test indicates that β-type titanium alloys，except c.p. Ti, exhibit a better bending fracture resistance, compared to both α〞/β and α′-type titanium alloys，especially Ti-15Mo-1Bi alloy。
　Then, the study compares castability, mechanical performance and deflection fatigue behavior among c.p. Ti, Ti-6Al-7Nb and newly-developed Ti-15Mo-1Bi alloys in their as-cast state. Experimental results indicate that average cast length of Ti-6Al-7Nb appears a little lower than c.p. Ti and Ti-15Mo-1Bi, although the differences are not significant. C.p. Ti has a hcp α phase of lath-type morphology with serrated, irregular grain boundaries. Ti-6Al-7Nb is dominated by hexagonal α′ phase with acicular martensitic morphology, while Ti-15Mo-1Bi is comprised of equiaxed, metastable bcc β phase. The hardened layer thicknesses of three materials are similar. Ti-15Mo-1Bi has the highest surface microvickers hardness, while c.p. Ti has the lowest. The bulk hardness of c.p. Ti is much lower than two alloys which have similar hardness. Ti-15Mo-1Bi and Ti-6Al-7Nb have similar bending strength which is far higher than c.p. Ti. The bending modulus of Ti-15Mo-1Bi is significantly lower than c.p. Ti and Ti-6Al-7Nb. Ti-15Mo-1Bi also shows a much larger elastic recovery angle than two other materials. Tensile test indicates that Ti-15Mo-1Bi has a similar UTS but much higher YS and elongation, along with much lower tensile modulus than Ti-6Al-7Nb. Deflection fatigue test shows that Ti-15Mo-1Bi has the highest fatigue life, while c.p. Ti has the lowest.

Ahmed T, Rack HJ. Phase transformations during cooling in α + β titanium alloys. Mater Sci Eng A, 243, 206-11, 1998.
Ahmed T, Long M, Silvestri J, Ruiz C, Rack HJ. in Titanium `95: Science and Technology, ed. Blankinsop PA, Evans WJ, Flowers HM. The Materials Society, London 1996; pp. 1760-7.
Ahmned T, Rack HJ. Low modulus biocompatible titanium base alloys for medical devices. US Patent No. 5871595, 1999.
Akahori T, Niinomi M. Fracture characteristics of fatigued Ti-6Al-4V ELI as an implant material, Mater Sci Eng A, 243, 237-43, 1998.
Ankem S, Greene SA. Recent developments in microstructure/property relationships of beta titanium alloys. Mater Sci Eng A, 263, 127-31, 1999.
Bagariaskii IA, Nosova GI, Tagunova TV. Factors in the formation of metastable phase in titanium-based alloys [Engl. trans.]. Sov Phys Dokl, 3, 1014-8, 1959.
Bania PJ. Beta titanium alloys and their role in the titanium industry. In: Eylon D, Boyer R, Koss D, editors. Beta titanium alloys in the 1990's. Warrendale, PA: TMS, p. 3-14, 1993.
Barbenel JC, Nicol S. Development of reference loading spectrum. MTS-Project AM1 Final Report, AEA Technology, 1996.
Bobyn JD, Mortimer ES, Glassman AH, Engh CA, Miller J, Brooks C. Producing and avoiding stress shielding: laboratory and clinical observation of noncemented total hip arthroplasty. Clinical Orthop. Relat. Research, 274, 79-96, 1992.
Brooks CR, Choudhury A. Fracture mechanisms and microfractographic features. In: Brooks CR, Choudhury A. editors. Metallurgical failure analysis Chap. 3, McGraw-Hill, New York, 1993.
Cheal E, Spector M, Hayes W. Role of loads and prosthesis material properties on the mechanics of the proximal femur after total hip arthroplasty. J Orthop Res, 10, 405-22, 1992.
Cheng WW, Chern Lin JH, JU CP. Effect of alloying addition on castability and other properties of titanium. AFS Trans, 01-169, 987-96, 2001.
Clemson Advisory Board for Biomaterials. “Definition of the word biomaterial”, Thc 6th Annnal Intermalionel Biomaterial Symposium, April 20-24, 1974.
Collings EW. The physical metallurgy of titanium alloys, ASM Series in Metal Processing. Gegel HL, editor. Cleveland, Metals Park, OH: American Society for Metals, 1984.
Couper MJ, Neeson AE, Griffiths JR. Casting defects and the fatigue life of an aluminum casting alloy. Fatigue Fract Eng Mater Struct, 13, 213-20, 1997.
Ragone DV, Adams CM, Taylor HF. AFS Trans. 64 (1956) 640-653.
Davidson JA, Kovacs P. Biocompatible low-modulus titanium alloy for medical implants. US Patent No. 5169597, 1992.
Davidson JA. Titanium molybdenum hafnium alloys for medical implants and device. US Patent No. 5954724, 1999.
Davis R, Flower HM, West DRF. Martensitic transformations in Ti-Mo alloys. J Mater Sci, 14, 712-22, 1979.
Dobbs HS, biomaterials, vol1, 1980, 193-8.
Dobromyslov AV, Elkin VA. βα〞 and βω transformations in Ti-Os alloys. Metallurgical and Materials Transactions A, 30, 231-2, 1999.
Donachie MJ. Relationships of properties and process. In: Donachie MJ editor, Titanium: a technical guide Chap. 11, ASM International: Metal Park, OH,. p. 157-206, 1989.
Duerig TW, Albrecht J, Richter J, Fischer P. Acta Metal, 30, 2161, 1982.
Duerig TW, Pelton AR, Stöckel D. The use of superelasticity in medicine. Metall, 50, 569-74, 1996.
Dumbleton JH., J Biomater Appl , vol 3, 1988, p3-32.
Eylon D, Strope B. Fatigue crack initiation in Ti-6wt%Al-4wt%V castings. J Mater Sci, 14, 117-23, 1979.
Fedotov SG. Peculiarities of changes in elastic properties of Ti martensite. Titanium Science and Technology, 2, 871-81, 1973.
Filip R, Kubiak K, Ziaja W, Sieniawski J. The effect of microstructure on the mechanical properties of two-phase titanium alloys. J Mater Process Technol, 133, 84-9, 2003.
Garcia R, Gorin S. Failure of posterior titanium atlantoaxial cable fixation: case studies. Spine J, 3, 166-70, 2003.
Goel VK, Lim TH, Gwon J, Chen JY, Winterbottom JM, Park JB, Weinstein JN, Ahn JY. Effects of rigidity of an internal fixation device: a comprehensive biomechanical investigation. Spine, 16, S155-61, 1991.
Goodman SB, Fornasier VL, Lee J and Kei J. The histological effects of the implantation of different sizes of poltethylene particles in the rabbit tibra. J Biomed Mater Res, 24, 517-24, 1990.
Guha A. Metals Handbook, 9th ed., 8 (ASM International, Metals Park, OH, 1985) pp. 133-6.
Hamanaka H, Doi H, Yoneyama T, Okuno O. Dental casting of titanium and Ni-Ti alloys by a new casting machine. J Dent Res, 68, 1529-33, 1989.
Hampel H, Piehler HR. Evaluation of the corrosion fatigue behavior of porous coated Ti-6Al-4V. edited by Brown SA and Lemons JE, Medical Applications of Titanium and Its Alloys: The Material and Biological Issues, ASTM STP 1272, West Conshohocken, PA: ASTM, 136-148, 1996.
Ho WF, Ju CP, Chern Lin JH. Structure and properties of cast binary Ti-Mo alloys. Biomaterials, 20, 2115-22, 1999.
Hoeppner DW, Chandrasekarn V. Fretting in orthopaedic implants: a review. Wear, 173, 189–97, 1994.
Huckstep RL. Early mobilization and rehabilitation in orthopaedic conditions. Aust NZJ Surg, 47, 344-53, 1977.
Ida K, Tani Y, Tsutsumi S, Togaya T, Nambu T, Suese K, Kawazoe T, Nakamura M. Clinical application of pure titanium crown. Dent Mater J, 4, 191-5, 1985.
Ida K, Togaya T, Tsutsumi S, Takeuchi M. Effect of magnesia investments in the dental casting of pure titanium and titanium alloy. Dent Mater J, 1, 8-21, 1982.
Imam MA, Fraker AC. Titanium alloys as implant materials. In: Brown SA, Lemons JE, editors. Medical applications of titanium and its alloys: the material and biological issues, ASTM STP, vol. 1272. West Conshohocken, ASTM, p. 3-16, 1996.
Jha SK, Ravichandran KS. High-cycle fatigue resistance in beta-titanium alloys. JOM, 30-5, 2000.
Jones LC, Hungerford DS. The photoelastic coating technique-its validation and use. Transactions of Orthopaedic Reach Society, 33, 306, 1987.
Kawahara H. Cytotoxicity of implantable metals and alloys. Bull Japan Inst Metals, 31, 1033-9, 1992.
Kawazoe T, Suese K. Clinical application of titanium crowns. J Dent Med, 30, 317-28, 1989.
Keavenly TM, Bartel DL. Fundamental load transfer patterns for press-fit, surface-treated intramedullary fixation stems. J Biomechanics, 27, 1147-57, 1994.
Kikuchi M, Takada Y, Kiyosue S, Yoda M, Woldu M, Cai Z, Okuno O, Okabe T. Mechanical properties and microstructures of cast Ti-Cu alloys. Dental Materials, 19, 174-81, 2003.
Kobayashi E, Wang TJ, Doi H, Yoneyama T, Hamanaka H. Mechanical properties and corrosion resistance of Ti-6Al-7Nb alloy dental casting. J Mater Sci Mater Med, 9, 567-74, 1998.
Koike M, Fujii H. The corrosion resistance of pure titanium in organic acids. Biomaterials, 22, 2931-6, 2001.
Kotake M, Wakabayashi N, Ai M, Yoneyama T, Hamanaka H. Fatigue resistance of titanium-nickel alloy cast clasps. Int J Prosthodont, 10, 547-52, 1997.
Kuroda D, Niinomi M, Morinaga M, Yosihisa K, Yashiro T. Design and mechanical properties of new β type titanium alloys for implant materials. Mater Sci Eng A, 243, 244-9, 1998.
Kuroiwa A, Igarashi Y. Application of pure titanium to metal framework. J Jpn Prosthodont Soc, 42, 547-58, 1998.
Laing PG, Fergosun AB, Hodge ES. Tissue reaction in rabbit muscle exposed to metallic implants. J Biomed Mater Res, 1, 135-49, 1967.
Lassila LV, Vallittu PK. Effect of water and artificial saliva on the low cycle fatigue resistance of cobalt-chromium dental alloy. J Prosthet Dent, 80, 708-13, 1998.
Lautenschlager EP, Monaghan P. Titanium and titanium alloys as dental materials. Int Dent J, 43, 245-53, 1993.
Lee CM, Ho WF, Ju CP, Chern Lin JH. Structure and Properties of Titanium-25Niobium-X Iron Alloys, J Mater Sci Mater Med, 13, 695-700, 2002.
Lee CM, Ju CP and Chern Lin JH. Structure-property relationship of cast Ti-Mo-Ta alloys. AFS Trans, accepted. 1999.
Lee CM, Ju CP and Chern Lin JH. Structure-property relationship of cast Ti-Nb alloys. J Oral Rehabil, 29, 314-22, 2000.
Lewis AJ. Failure of removable partial denture castings during service. J Prosthet Dent, 39, 147-9, 1978.
Long M, Crooks M, Rack HJ. High-cycle fatigue performance of solution-treated metastable-β titanium alloys. Acta Mater, 47, 661-9, 1999.
Long M, Rack HJ. Titanium alloys in total joint replacement-a materials science perspective. Biomaterials, 19, 1621-39, 1998.
McAfee PC, Farey ID, Sutterlin CE, Gurr KR, Warden KE, Cunningham BW. The effect of spinal implant rigidity on vertebral bone density: a canine model. Spine, 16, S190-7, 1991.
Mishra AK, Davidson JA, Poggie RA, Kovacs P, FitzGerald TJ. Mechanical and tribological properties and biocompatibility of diffusion hardened Ti-13Nb-13Zr – a new titanium alloy for surgical implants. In: Brown SA, Lemons JE, editors. Medical applications of titanium and its alloys: the material and biological issues, ASTM STP, vol. 1272. West Conshohocken, ASTM, p. 96-113, 1996.
Miyakawa O, Watanabe K, Okawa S, Nakano S, Kobayashi M Shiokawa N. Layered structure of cast titanium surface. Dent Mater J, 8, 175-85, 1989.
Morris H, Farah JW, Craig RG, Hood JA. Stress distribution within circumferential clasp arms. J Oral Rehabil, 3, 387-94, 1976.
Nakajima H, Okabe T. Titanium in dentistry: development and research in the USA. Dent Mater J, 15, 77-90, 1996.
Nan H, Yuanru C, Guangjun C, Chenggang L, Zhongguang W, Guo Y, Huehe S, Xianghuai L, Zhihong Z. Research on the fatigue behavior of titanium based biomaterial coated with titanium nitride film by ion beam enhanced deposition. Surface and Coatings Technology, 88, 127-31, 1996.
Niinomi M, Saga A, Fukunaga KI, Long crack growth behavior of implant material Ti-5Al-2.5Fe in air and simulated body environment related to microstructure. International Journal of Fatigue, 22, 887-97, 2000.
Niinomi M. Fatigue performance and cyto-toxicity of low rigidity titanium alloy, Ti-29Nb-13Ta-4.6Zr. Biomaterials, 24, 2673-83, 2003.
Niinomi M. Mechanical properties of biomedical titanium alloys. Mater Sci Eng A, 243, 231-6, 1998.
Oh I, Harris WH. Proximal strain distribution in the loaded femur. Journal of Bone and Joint Surgery, 60A, 75-85, 1978.
Okabe T, Herø H. The use of titanium in dentistry. Cell Mater, 5, 211-30, 1995.
Okazaki Y, Asao S, Rao S, Tateishi T. Effect of concentration of Zr, Sn, Nb, Ta, Pd, Mo, Co, Cr, Si, Ni, Fe on the relative growth ratios of biocells. J Japan Inst Metal, 60, 902-6, 1996.
Okazaki Y, Ito Y, Ito A, Takeishi T. Effect of alloying elements on mechanical properties of titanium alloys for medical implants. Mater Trans JIM, 34, 1217-22, 1993.
Okazaki Y, Ito Y, Kyo K, Tateishi T. Corrosion resistance and corrosion fatigue strength of new titanium alloys for medical implants without V and Al. Mater Sci Eng A, 213, 138-47, 1996.
Okazaki Y, Kyo K, Ito Y, Tateishi T. Effect of Mo and Pd on corrosion resistance of V-free titanium alloys for medical implants. Mater Trans JIM, 38, 344-52, 1997.
Papakyriacou M, Mayer H, Pypen C, Jr HP, Tschegg SS. Effects of surface treatments on high cycle corrosion fatigue of metallic implant materials. International Journal of Fatigue, 22, 873-86, 2000.
Park JB, Editor, Biomaterials science and engineering, Plenum Press, New York, 1989.
Patwardhan AG, Ghanayem AJ, Voronov LI, Zindrick MR. Effect of compressive preload on the anterior lumbar interbody fusion cage construct stability. Spine J, 2, 27-, 2002.
Perl DP, Brody AR. Alzeihmer’s disease: X-ray spectrometric evidence of aluminium accumulation in neurofibrillary tangle-bearing neurons. Science, 208, 297-9, 1980.
Porter LF and Rosenthal PC: AFS Trans. 60 (1952) 725-739.
Pourbaix M. Electrochemical corrosion of metallic biomaterials. Biomaterials, 4, 122-34, 1984.
Rae T. A study of the effects of particulate metal of orthopaedic interest on murine macrophrages in vitro. J Bone Jt Surg, 57, 444, 1975.
Rae T. The biological response to titanium and titanium-aluminium- vanadium alloy particles. Biomaterials, 7: 37-40, 1986.
Rao S, Ushida T, Tateishi T, Okazaki Y, Asao S. Effect of Ti, Al, and V ions on the relative growth rate of fibroblasts (L929) and osteoblasts (MC3T3-E1) cells. Biomed Mater Eng, 6, 79-86, 1996.
Rohlmann A, Bergmann G, Graichen F, Mayer HM. Placing a bone graft more posteriorly may reduce the risk of pedicle screw breakage: Analysis of an unexpected case of pedicle screw breakage. J Biomech, 31, 763-7, 1998.
Schultz A. Loads on the lumbar spine. In: Jayson MIV, ed. The lumbar spine and back pain. New York: Churchill Livingstone, p. 204-14, 1987.
Schutz RW. Environmental behavior of beta titanium alloys. JOM, 24-9, 1994.
Shimizu H, Habu T, Takada T, Watanabe K, Okuno O, Okabe T. Mold filling of titanium alloys in two different wedge-shaped molds. Biomaterials, 23, 2275-81, 2002.
Smith DC. Surface Characterization of Implant Material: Biological Implications, The Bone-Biomaterial Interface, edited by Davies JE, University of Toronto Press, Toronto Buffalo London, p. 3-18, 1991.
Steinemann SG. Corrosion of titanium and titanium alloys for surgical implants. Ti’84 Science and Technology. Ljering G, Zwicker U, Bunk W. editors, 1373, 1984.
Sumner DR, Galante JO. Determinants of stress shielding: design versus materials versus interface. Clin Orthop Relat Res, 274, 202-12, 1992.
Thompson GJ, Puleo DA. Ti-6Al-4V ion solution inhibhtion of osteogenic cell phenotype as a function of differentiation timecourse in vitro. Biomaterials, 17, 1949-54, 1996.
Ting JC, Lawrence FV. A crack closure model for predicting the threshold stresses of notches. Fatigue Fract Eng Mater Struct, 16, 93-114, 1993.
Tsutsue T, Kawaguchi H, Fujino A, Sakai H, Nakamura T. Exposure of macrophage-like cells to titanium particles does not affect bone resorption, but inhibits bone formation. Journal of Orthopaedic Science, 4, 32-8, 1999.
Ueyama Y, Naitoh R, Yamagata A, Matsumura T. Analysis of reconstruction of mandibular defects using single stainless steel A-O reconstruction plates. J Oral Maxillofac Surg, 54, 858-62, 1996.
Vallittu PK, Kokkonen M. Deflection fatigue of cobalt-chromium, titanium, and gold alloy cast denture clasp. J Prosthet Dent, 74, 412-9, 1995.
Vallittu PK, Lassila VP, Lappalainen R. Evaluation of damage to removable dentures in two cities in Finland. Acta Odontol Scand, 51, 363-9, 1993.
van Noort R. Titanium: the implant material of today. J Mater Sci, 22, 3801-11, 1987.
Velasquez H, Smith M, Foyos J, Fisher F, Es-Said OS. Low-cycle fatigue on titanium 6Al-4V surgical tools. Engineering failure analysis, 5, 7-11, 1998.
Walker PR, LeBlanc J, Sikorska M. Effects of aluminum and other cations on the structure of brain and liver chromatin. Biochemistry, 28, 3911-5, 1989.
Wallenstein S, Zucker CL, Fleiss JL. Some statistical methods useful in circulation research. Circ Res, 47, 1-9, 1980.
Wang K, Gustavson LJ, Dumbleton JH. Microstructure and properties of a new beta titanium alloy, Ti-12Mo-6Zr-2Fe, developed for surgical implants. In: Brown SA, Lemons JE, editors. Medical applications of titanium and its alloys: the material and biological issues, ASTM STP, vol. 1272. West Conshohocken, ASTM, p. 76-87, 1996.
Wang K. The use of titanium for medical applications in the USA. Mater Sci Eng A, 213, 134-7, 1996.
Watanabe K, Miyakawa O, Takada Y, Okuno O, Okabe T. Casting behavior of titanium alloys in a centrifugal casting machine. Biomaterials, 24, 1737-43, 2003.
Weiss I, Semiatin SL. Thermomechanical processing of beta titanium alloys – an overview. Mater Sci Eng A, 243, 46-65, 1998.
Wilson SAV, Freeman MAR, editors, The Scientific Basis of Joint Replacement, Wwiley, New York, 1977.（in Park JB, Editor, Biomaterials science and engineering, 1984 Plenum Press, New York.）
Wolff J, Das Gesetz Der Transformation Der Knochen, Hirshwald Verlag, Berlin, 1892.
Yli-Urpo A, Lappalainen R, Huuskonen O. Frequency of damage to and need for repairs of removable dentures. Proc Finn Dent Soc, 81, 151-5, 1985.
Yokoyama K, Ichikawa T, Murakami H, Miyamoto Y, Asaoka K. Fracture mechanisms of retrieved titanium screw thread in dental implant. Biomaterials, 23, 2459-65, 2002.
Yumoto S, Ohashi H, Nagai H, Kakimi S, Ogawa Y, Iwata Y, Ishii K. Aluminum neurotoxicity in the rat brain. Int J of PIXE, World Scientific Publishing Company, 2, 493-504, 1992.
Zardiakas LD, Michell DW, Disegi JA. Characterization of Ti-15Mo beta titanium alloy for orthopaedic implant applications. In: Brown SA, Lemons JE, editors. Medical applications of titanium and its alloys: the material and biological issues, ASTM STP, vol. 1272. West Conshohocken, ASTM, p. 60-75, 1996.
Zhu J, Kamiya A, Yamada T, Shi W, Naganuma K. Influence of boron addition on microstructure and mechanical properties of dental cast titanium alloys. Mater Sci Eng A, 339, 53-62, 2003.