近年來，積層製造的技術在各個領域被運用的越來越多，因其一步化的製程以及客製化的設計使其在生醫植入物及航空產業的應用越來越廣泛。其中以逐層電子束熔化印製的製程為最有淺力的積層製造技術之一。然而，電子束熔化的製程會因為熔池導致相鄰的粉末顆粒在熔融的狀態燒結到表面使的表面變粗糙。在動態應力的環境下，可能因為這些表面的粉末顆粒形成的缺口造成應力集中進而疲勞。因此，需要藉由各種不同的表面後處理來改善表面粗品質。另一方面，由於傳統的機械拋光無法對複雜或是內部的結構進行拋光。因此，電解拋光是改善Ti6Al4V EBM樣品表面品質的一種可行方法。
本研究將評估電解拋光是否為一有效的表面改質方法。第一部份先找出對Ti6Al4V EBM樣品的最佳電解液及參數。第二部份，藉由觀察表面形貌及試片表面的缺口來討論應力集中的影響。第三部分，藉由測量楊氏係數，伸長量和降伏強度來討論不同表面粗糙對機械性質的影響；最後對多孔結構的試片進行電解拋光並用斷層掃描技術來探討內部結構的表面粗糙度。
實驗結果顯示，利用過氯酸、冰醋酸和乙醇的電解液電解拋光Ti6Al4V EBM實心非多孔之樣品的表面，其粗糙度可由23.4μm減小到5.3μm。使用最佳電解拋光條件，施用於Ti6Al4V EBM車製之拉伸試片，其拉伸試片側表面的粗糙度可由24.1μm減小到4.1μm，拉伸試片之伸長率可從7.6％ 增加到11.6％。然而，對於多孔Ti6Al4V EBM之壓縮試片，其結果顯示，拋光的多孔試片由於其外部支架的過度腐蝕，使其機械性質比未拋光的多孔試片反而更差。

During the past years, the use of additive manufacturing (AM) technologies in a variety of fields has increased substantially. Because of the one-step manufacture and customization of designs, AM technologies have been more and more widely used in the application of the medical implants and aerospace components.

Electron beam melting (EBM), which involves the layer-by-layer electron beam melting of powders, is one of the most promising AM technologies. However, the procedure of EBM process will make products get rougher surface due to melting pool which causes adjacent powder particles to be sintered to the surface without being melted. Under dynamic stress, notches caused by these bounded powders may cause stress concentration and may induce products fatigue. Hence, it is necessary to improve the surface quality by various post processes. On the other hand, internal or complicate structures are impossible to finish by conventional mechanical polishing methods. Therefore, electropolishing is a feasible method to improve the surface quality of Ti6Al4V EBM samples.

This study is devoted to evaluating whether the electropolishing method would be the effective method or not. Firstly, the best electrolyte and parameters for Ti6Al4V EBM samples are searched out by different experimental condition designs. Secondly, surface quality, such as surface morphology and notches on the surface, are observed with a view to discussing the influence of stress concentration. Thirdly, mechanical properties, such as Young’s modulus, elongation, and yield stress, are measured to discuss the influence of different degrees of roughness on the surface. Lastly not the least, the electropolished-porous samples are analyzed by micro-CT.

Experiment results show that the surface roughness of Ti6Al4V EBM solid samples can be improved from 23.4 μm to 5.3 μm by electropolishing with the electrolyte of perchloric acid, glacial acetic acid, and ethanol. For the Ti6Al4V EBM solid tensile specimens after optimum electropolishing, the tensile elongation can increase from 7.6% to 11.6%, with the surface roughness of the side surface of tensile specimen decreasing from 24.1 μm to 4.1 μm. However, for the porous Ti6Al4V EBM compression specimens, the results show that the polished porous specimens would result in worse mechanical property than the unpolished porous specimen, as a result of the over corrosion of external ligaments.

論文審定書 i
誌謝 ii
摘要 iv
Abstract vi
List of Tables xi
List of Figures xii
Chapter 1 Introduction 1
1-1 Bio-implant materials 1
1-2 Additive manufacture 1
1-3 Motivation 2
Chapter 2 Background and Literature Review 4
2-1 Biomaterials 4
2-2 Different types of biomaterials 5
2-2-1 Metals and alloys biomaterials 5
2-2-2 Polymeric biomaterials 6
2-2-3 Ceramics biomaterials 7
2-3 Additive manufacturing (AM) 8
2-3-1 Electron beam melting (EBM) 11
2-3-2 Advantages of additive manufacturing 13
2-3-3 Obstacles of additive manufacturing 14
2-4 Post processing methods 16
2-4-1 Vibratory grinding 16
2-4-2 Abrasive blasting 17
2-4-3 Electropolishing 17
2-5 Introduction of titanium (Ti) and alloys 19
2-5-1 Alpha (α) stabilizers and α-type Ti-based alloys 20
2-5-2 Beta (β) stabilizers and β-type Ti-based alloys 21
2-5-3 α+β Ti-based alloys 21
2-6 Porous titanium and its alloys 23
Chapter 3 Experimental procedures 26
3-1 Materials 26
3-1-1 Raw material powders 26
3-1-2 Powder recovery system (PRS) 26
3-2 EBM of AM 27
3-3 Electropolishing (EP) 27
3-4 Property measurement and analyses 28
3-4-1 X-ray diffraction 28
3-4-2 Porosity measurement 29
3-4-3 Scanning electron microscopy 29
3-4-4 Universal testing machine 30
3-4-5 Alpha step 30
Chapter 4 Results and discussions 31
4-1 XRD analysis 31
4-2 SEM analysis 32
4-3 Electropolishing analysis 33
4-4 Tensile test results 35
4-5 Compression testing 37
Chapter 5 Conclusions 41
References 42
Tables 47
Figures 52

[1] U. K. Mudali, T.M. Sridhar, B. Raj, Sadhana Academy Proceeding in Engineering Science, 28 (2003), 601-637.
[2] S. R. Paital, N.B. Dahotre, Materials Science and Engineering R, 66 (2009), 1-70.
[3] M. Long, H.J. Rack, Biomaterails, 19 (1998), 1621-1639.
[4] S. S. Hakki, S. B. Bozkurt, E. E. Hakki, P. Korkusuz, N. Purali, N. Koc, M. Timucin, A. Ozturk, F. Korkusuz, Biomedical Materials, 7 (2012), 045006.
[5] R. huiskes, Acta orthopaedical. Belgica, 59 (1993), 118-129.
[6] R. Bogue, Assembly Automation, 33 (2013), 307-311
[7] I. Gibson, D.W. Rosen, B. Stucker, Additive manufacturing technologies, Springer, 2010.
[8] J. Parthasarathy, B. Starly, S. Raman, A. Christensen, Journal of the Mechanical Behavior of Biomedical Materials, 3 (2010), 249-259.
[9] D. Greitemeier, C. Dalle Donne, F. Syassen, J Eufinger, T. Melz, Materials Science and Technology, 32 (2016), 629-634.
[10] Y. J. Liu, S. J. Li, H. L. Wang, W. T. Hou, R. Yang, T. B. Sercombe, L. C. Zhang, Acta Materialia, 113 (2016), 56-67.
[11] G. W. Critchlow, D. M. Brewis, International Journal of Adhesion and Adhesives, 15 (1995), 161-172.
[12] H. K. Rafi, N. V. Karthik, Haijun Gong, Thomas L. Starr, Brent E, Stucker, Journal of Material Engineering and Performance, 22 (2013), 3872-3883.
[13] C. P. Bergman, A. Stumpf, Dental Ceramics, Springer, 2013.
[14] 吳文騰, 生物產業技術概論, 國立清華大學出版社, 2003.
[15] Q. Chen, G. A. Thouas, Material Science and Engineering R, 87 (2015), 1-57.
[16] J. R. Davis, Handbook of Materials for Medical Devices, 2003, 21-50.
[17] J. R. Cahoon, Richard N. Hotle, Journal of Biomedical Materials Research, 15 (1981), 137-145.
[18] Y. Luo, L. Yang, M. Tian, Biomater. Medical Tribology, 2013, 181-216.
[19] N. Angelova, D. Hunkeler, Trends in Biotechnology, 17 (1999), 409-421.
[20] A. R. Boccaccini, J. Gough, Tissue Engineering Using Ceramics and Polymers, Woodhead publishing, 2014.
[21] M. Attaran, Business Horizons, 60 (2017), 677-688.
[22] B. Redwood, Additive Manufacturing Technologies: An Overview, 3D Hubs, 2018.
[23] https://proto3000.com/polyjet-matrix-3d-printing-services-process.php.
[24] D. I. Wimpenny, B. Bryden, I. R. Pashby, Journal of Materials Processing Technology, 138 (2003), 214-218.
[25] V. Bhavar, P. Kattire, V. Patil, S. Khot, K. Gujar, R. Singh, A review on powder bed fusion technology of metal additive manufacturing, 4th international conference and exhibition on Additive Manufacturing Technologies, 2014.
[26] S. L. Sing, J. An, W. Y. Yeong, F. E. Wiria , Journal of Orthopaedic Reasearch, 34 (2016), 369-385.
[27] L.E. Murr, S. Gaytan, A. Ceylan, E. Martinez, J. Martinez, D. Hernandez, B. Machado, D. Ramirez, F. Medina, S. Collins, Acta Material, 58 (2010), 1887-1894.
[28] X. Zhao, S. Li, M. Zhang, Y. Liu, T. B. Sercombe, S. Wang, Y. Hao, R. Yang, L. E. Murr, Material & Designs, 95 (2016), 21-31.
[29] X. Gong, T. Anderson, Manufacturing Review, EDP Sciences, 1 (2014).
[30] L. E. Murr, E. Martinez, K. N. Amato, S. M. Gaytan, J. Hernandez,
D. A. Ramirez, P. W. Shindo, F. Medina, R. B. Wicker, Journal of Materials Research and Technology, 1 (2012), 42-54.
[31] B. Vayre, F. Vignat, F. Villeneuve, Prodedia CIRP, 7 (2013), 264-269.
[32] R. Udroiu, Academic Journal of Manufacturing Engineering, 10 (2012), 122-129.
[33] X. Tan, Y. Kok, Y.J. Tan, M. Descoins, D. Mangelinck, S.B. Tor, K.F. Leong, C.K. Chua, Acta Material, 97 (2015), 1-16.
[34] J.M. Dowden, The Mathematics of Thermal Modeling: An Introduction to the Theory of Laser Material Processing, CRC Press Incorporated, Boca Raton, 2001.
[35] P. Lemasson, M. Carin, J.C. Parpillon, R. Berthet, International Journal of Heat and Mass Transfer, 46 (2003), 4553-4559.
[36] M. Courtois, M. Carin, P.L. Masson, S. Gaied, M. Balabane, Journal of Physics D: Applied Physics, 46 (2013), 505305.
[37] Q. Tang, S. Pang, B. Chen, H. Suo, J. Zhou, International Journal of Heat and Mass Transfer, 78 (2014), 203-215.
[38] M. Geiger, K.H. Leitz, H. Koch, A. Otto, Production Engineering, 3 (2009), 127-136.
[39] R. S. Zhou, F. Hashimoto, Journal of Tribology, 117 (1995), 166-170.
[40] F. Hashimoto, D. B. DeBra, CIRP Annals Manufacturing Technology, 45 (1996), 303-306.
[41] http://compomat.com/what-is-abrasive-blasting/
[42] N. Perez, Electrochemistry and Corrosion Science, Springer, 2004.
[43] D. Landolt, Electrochimica Acta, 32 (1987), 1-11.
[44] T. P. Hoar, D. C. Mears, G. P. Rothwell, Corrosion Science, 5 (1965), 279-289.
[45] C. Cleric, M. Datta, D. Landolt, Electrochimica Acta, 29 (1984), 1477-1486.
[46] M. Datta, L. F. Vega, L. T. Romankiw, P. Duby, Electrochimica Acta, 37 (1992), 2469-2475.
[47] E. K. Molchanova, Phase diagrams of titanium alloys, Israel Program for Scientific Translation, 1965.
[48] R. Pederson, O. Babushkin, F. Skystedt, R. Warren, Material Science and Technology, 19 (2003), 1533-1538.
[49] M. McQuillan, Metallurgical Reviews, 8 (1963), 41-104.
[50] G. Lütjering, Materials Science and Engineering: A, 243 (1998), 32-45.
[51] R. Pederson, Microstructure and phase transformation of Ti-6Al-4V, Lulea University of Technology, 2002.
[52] Y. Y. Zong, S. H. Huang, B. Guo, D. B. Shan, Transactions of Nonferrous Metals Society of China, 25 (2015), 2901-2911.
[53] M. Jovanovic, S. Tadic, S. Zec, Z. Miskovic, I. Bobic, Materials & design, 27 (2006), 192-199.
[54] C. Suryanarayana, M. Grant Norton, X-Ray Diffraction: A Practical Approach, Springer Science & Business Media, 1998.
[55] L. J. Gibson, M. F. Ashby, Proceedings of the Royal Society of London A: Mathematical, Physical and Engineering Sciences, The Royal Society, (1982), 43-59.
[56] C. E. Wang, Y. Yamada, P. D. Hodgson, Materials Science and Engineering: C, 26 (2006), 1439-1444.
[57] A. Clemow, A. Weinstein, J. Klawitter, J. Koeneman, J. Anderson, Journal of Biomedical Material Research, 15 (1981), 73-82.
[58] X. J. Wang, S. Q. Xu, S. W. Zhou, W. Xu, M. Leary, P. Choong, M. Qian, M. Brandt, Y. M. Xie, Biomaterials, 83 (2016), 127-141.
[59] V. Karageorgiou, D. Kaplan, Biomaterials, 26 (2005), 5474-5491.
[60] Y. T. Jian, Y. Yang, T. Tian, C. Stanford, X. P. Zhang, K. Zhao, PLoS ONE, 10 (2015), 1-10.
[61] A. Roberts, E. J. Garboczi, Journal of the Mechanics and Physics of Solids, 50 (2002), 33-55.
[62] V. Urlea, V. Brailovski, Journal of Materials Processing Technology, 242 (2017), 1-11.