本研究旨在探討不同的真空鑄造製程參數對鎂合金（Magnesium alloy）缺陷面積的影響，以及深入探討在等徑轉角擠型(equal channel angular pressing, ECAP)製程所造成的微觀結構演變，材料機械性質的改變，並以「田口方法」結合「X光影像非破壞性檢測儀」檢驗內部缺陷面積百分比(Percentage of internal defect area, PIDA），以進行ECAP的製程最適化參數組合，並以實驗驗證其結果。
在影像處理方面，本研究將鎂合金試片X光影像作濾波、二值化、邊緣強化及形態學計算內部缺陷面積;PIDA分析將可應用加熱溫度、恆溫時間等製程參數，輔助探討材料性質的多重品質特性指標（Multiple performance characteristics index, MPCI），以供最佳化製程之設計開發。
經田口方法實驗結果，本研究得到在以下條件組合 (溫度720 ℃， 真空30 torr， 恆溫時間2 hr， 加熱介質鋼珠，並以微量氩氣通入120 min.) 及以上參數 (780 ℃, 30 torr, 1 hr, steel, Ar 120 min.) 是較佳組合配列) ，其中又以批次8之PIDA變異量小，製程較穩定。鎂基複合材料ECAP製程之最適化製程參數組合為：強化相添加量2%、ECAP 2道次、AZ61鎂合金及轉角角度120°。此結果也顯示田口方法結合MPCI設計在最適化製程參數分析的可行性。

This study is devoted to investigating the influence of vacuum casting parameters on defects in magnesium alloy, and to exploring the changes in the mechanical properties and microstructural evolution under equal channel angular pressing(ECAP). The Taguchi method in conjunction with an X-ray image detector was employed to determine the percentage of internal defect area (PIDA). X-ray images of magnesium alloy specimens were filtered, binarized, and edge enhanced. The calculated area of internal defects was then used to optimize process parameters according to multiple performance indicators. Based on experimental results, the combination of temperature 720℃, vacuum 30 torr, for 2 hours, steel, and 120 min of argon gas injection and parameters (780℃, 30 torrs, 1 hours, steels, and 120 min of argon gas injection) were both deemed optimal. The uniformity in the percentage of internal defect area observed in samples from Batch 8 is an indication of stability. Taguchi with MPCI analysis led to the following optimal combination of parameters: addition of reinforcement pass two wt. % processed two passes, AZ61 and with an angle of 120° of ECAP MMCs were both deemed optimal and verified its results experimentally.

[1] D, Mery, “Computer vision technology for X-ray testing.” Insight, Vol. 56, No. 3, pp. 147-155, 2014
[2] S. J. Huang, P. C. Lin, B. Ballóková, P. Hvizdos, M. Besterci, “Tribological behaviour and local mechanical properties of magnesium-alumina composites, Kovove Materialy-Metallic Materials,” Vol. 52, No. 5, pp. 313-319, 2014
[3] C. M. Lin, J. J. Liu, H. L. Tsai, C. M. Cheng, “Evolution of microstructures and mechanical properties of AZ31B magnesium alloy weldmentwith active oxide fluxes and GTAW process,” Journal of the Chinese Institute of Engineers, Vol. 34, No. 8, pp. 1013-1023, 2011
[4] C. H. Chien, W. B. Lin, T. Chen, “Optimal FSW process parameters for aluminum alloys AA5083,” Journal of the Chinese Institute of Engineers, Vol. 34, No. 1, pp. 99-105, 2011
[5] K. A. Patwardhan, Student Member, “Robust Foreground Detection in Video Using Pixel Layers,” IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 19, No. 7, pp. 746-751, 2008
[6] Y. Benezeth, B. Emile, C. Rosenberger, “Comparative Study on Foreground Detection Algorithms for Human Detection,” IEEE Computer Society of the Fourth International Conference on Image and Graphics, pp. 661-666, 2007
[7] T. Dubroca G. Brown, R. E. Hummel “Detection of explosives by differential hyperspectral imaging,” Optical Engineering, Vol. 53, No. 2, pp. 1-7, 2014
[8] I. Latos, M. L. Jano'czki, “Stability investigations of automatic X- ray inspection systems,” Soldering & Surface Mount Technology, Vol. 23, No. 2, pp.91-103, 2011
[9] Z. Pei, Y. Zhang, X. Chen, Y. H. Yang, “Synthetic aperture imaging using pixel labeling via energy minimization,” Pattern Recognition, Vol. 46, pp. 174-187, 2013
[10] M. V. Chukalina, et al., “Optophysical measurements: X-ray microtomography using a laboratory source: Measurement technique and comparison of reconstruction algorithms,” Measurement Techniques, Vol. 51, No. 2, pp.136-145, 2008
[11] P. L. Shui, W. C Zhang, “Corner detection and classification using anisotropic directional derivatives representations,” IEEE Transactions on image processing, Vol. 22, pp. 3204-3218, 2013
[12] S. Sua´rez, E. Ramos-Moore, B. Lechthaler, F. Mu¨cklich, “Grain growth analysis of multiwalled carbon nanotube-reinforced bulk Ni composites,” Carbon, Vol. 70, pp. 173 -178, 2014
[13] M. Manoharan, S.C.V. Lim, M. Gupta, “Application of a model for the work hardening behavior to Mg/SiC composites synthesized using a fluxless casting process,” Materials Science and Engineering A, Vol. 333, pp.243-249, 2002
[14] C. S. Goh, J. Wei, L. C. Lee, M. Gupta, “Simultaneous enhancement in strength and ductility by reinforcing magnesium with carbon nanotubes,” Materials Science and Engineering A, Vol. 423, pp. 153-156, 2006
[15] K. K. Deng, X. J. Wang, Y. W. Wu, X. S. Hu, K. Wu, W. M. Gan, “Effect of particle size on microstructure and mechanical properties of SiCp/AZ91 magnesium matrix composite,” Materials Science and Engineering A, Vol. 543, pp. 158-163, 2012
[16] I. K. Ashiri, S. R. Cohen, K. Gartsman, V. Ivanovskaya, T. Heine, G. Seifert, I. Wiesel, H. D. Wagner, R. Tenne, “On the mechanical behavior of WS2 nanotubes under axial tension and compression,” Proceedings of the National Academy of Sciences, Vol. 103, pp. 523-528, 2005
[17] B. W. Chua, L. Lu, M. O. Lai, “Infuence of SiC particles on mechanical properties of Mg based composite,” Composite Structures, Vol. 47, pp. 595-601, 1999
[18] S. F. Hassan, M. Gupta, “Development of high performance magnesium nano-composites using nano-Al2O3 as reinforcement,” Materials Science and Engineering A, Vol. 392, pp. 163-168, 2005
[19] V. M. Segal, “Materials Processing by Simple Shear”, Materials Science and Engineering A, Vol. 197 pp.157-164, 1995
[20] V. M. Segal, K.T. Hartwig, R. E. Goforth, “In situ composites processed by simple shear”, Materials Science and Engineering A, Vol. 224, pp.107-115, 1997
[21] V. M. Segal, K. T. Hartwig USSR Patent No. 575892, 1997
[22] R. Z. Valiev, T. G. Langdon, “Principles of equal-channel angular pressing as a processing tool for grain refinement,” Progress in Materials Science Vol. 51, pp. 881-981, 2006
[23] K. Matsubara, Y. Miyahara, Z. Horita, T. G. Langdon, “Developing superplasticity in a magnesium alloy through a combination of extrusion and ECAP,” Acta Materialia, Vol. 51, pp. 3073-3084, 2003
[24] F. Kang, J. T. Wang, Y. Peng, “Deformation and Fracture during Equal Channel Angular Pressing of AZ31 Magnesium Alloy,” Materials Science and Engineering A, Vol. 487, pp. 68-73, 2008
[25] H. K. Kim, W. J. Kim,“Microstructural instability and strength of an AZ31 Mg alloy after severe plastic deformation,” Materials Science and Engineering A, Vol. 385, pp. 300-308, 2004
[26] K. Xia, J. T. Wang, X. Wu, G. Chen, M. Gurvan, “Equal channel angular pressing of magnesium alloy AZ31,” Materials Science and Engineering A, Vol. 410-411, pp. 324-327, 2005
[27] T. Mukai, M. Yamanoi, H. Watanabe, K. Ishikawa, K. Higashi, “Effect of grain refinement on tensile ductility in ZK60 magnesium alloy under dynamic loading,” Materials Transactions, Vol. 45, pp. 1177-1181, 2001
[28] S. R. Agnew, J. A. Horton, T. M. Lillo, D. W. Brown,” Enhanced ductility in strongly textured magnesium produced by equal channel angular processing,” Scripta Materialia, Vol. 50, pp. 377-381, 2004
[29] W. J. Kim, C. W. An,Y. S. Kim, S. I. Hong, “Mechanical properties and microstructures of an AZ61Mg Alloy produced by equal channel angular pressing,” Scripta Materialia, Vol. 47, pp.39-44, 2002
[30] M. Furukawa, Z. Horita, T. G. Langdon, “Factors influencing the shearing patterns in equal-channelangular pressing”, Materials Science and Engineering A, Vol. 332, pp. 97-109, 2002
[31] C. Pithan, T. Hashimoto , “Microstructure and texture evolution in ECAE processed A5056”,Materials Science and Engineering A, Vol. 280 pp. 62-68, 2000
[32] S. J. Huang, P. C. Lin. “Grain refinement of AM60/Al2O3p magnesium metal-matrix composites processed by ECAE,” Kovove Materialy-Metallic Materials, Vol. 51, pp. 357-366, 2013
[33] C. C. Lin, S. J. Huang, C. C. Liu, “Structural analysis and optimization of bicycle frame designs,” Advances in Mechanical Engineering, Vol. 9, No. 11, pp. 1-10, 2017
[34] T. J. Marrow, M. Mostafavi, T. Hashimoto, et al. “A quantitative three-dimensional in situ study of a short fatigue crack in a magnesium alloy.” International Journal of Fatigue; Vol. 66, pp. 183-193, 2014
[35] Q. Wan, H. ZHAO, C. Zou. “Effect of micro-porosities on fatigue behavior in aluminum die castings by 3D X-ray tomography inspection.” ISIJ International, Vol. 54, pp. 511-515, 2014
[36] K. Kan, Y. Imura, H. Morii, et al. “Application of photon-counting X-ray computed tomography to aluminum-casting inspection.” World Journal of Nuclear Science and Technology, Vol. 3, No. 3, pp. 106-108, 2013
[37] H. Bay , A. Ess, T. Tuytelaars, L. V. Gool, Speeded-Up Robust Features (SURF), Computer Vision and Image Understanding, Vol. 110 pp. 346-359, 2008
[38] 桜井健次, “Introduction to X-ray Reflectivity X線反射率法入門,” 講談社, 2009年6月.
[39] S. J. Huang, Y. C. Lin, “Fracture analysis for adhesively bonded sandwich beam under mode-I loading,” Journal of Adhesion Science and Technology, Vol. 18, No. 7, 2004
[40] O. Velgosova, M. Besterci, P. Kulu, S. J. Huang, “Effect of strain rate, volume fraction and temperature on fracture mechanism of the dispersion strengthened Al-Al4C3 system,” Kovove Materialy- Metallic Materials, Vol. 49, No.5, pp. 361-367, 2011
[41] H. R. Ezatpour, S. A. Sajjadi, M. H. Sabzevar, Y. Huang, “Investigation of microstructure and mechanical properties of Al6061-nanocomposite fabricated by stir casting”, Materials and Design, Vol. 55, pp.921-928, 2014.
[42] S. J. Huang, C. C. Lin, F. J. Shiou, J. Y. Huang, “Process parameter optimization of magnesium alloy quasi-vacuum casting using X-Ray image defect inspection,” Kovove Materialy-Metallic Materials, Vol. 55, No. 5, pp. 343-350, 2017
[43] S. J. Huang, C. C. Lin, J. Y. Huang, “Mechanical behavior enhancement of AZ31/WS2 and AZ61/WS2 magnesium metal-matrix nanocomposites,” Advances in Mechanical Engineering, Vol. 10, No2. pp. 1-14, 2018
[44] C. Karunakaran, D. S. Jayas, N. D. G. White. “Soft X-ray inspection of wheat kernels infested by Sitophilus oryzae,” Transactions of the ASAE Vol. 46, No3. pp 739-745, 2003.
[45] C. Karunakaran, D. S. Jayas, N. D. G. White. “Detection of internal wheat seed infestation by Rhyzopertha dominica using X-ray imaging.” Journal of Stored Products Research Vol. 40, pp. 507-516, 2004.
[46] M. U. Reyes, R. E. Paull, J. W. Armstrong, P. A. Follett, L. D. Gautz. “Non-destructive inspection of mango fruit (Mangifera indica L.) with soft X-ray imaging.” Acta Horticulturae Vol. 509, pp.787-792, 2000.
[47] E. C. Yang, M. M. Yang, L. H. Liao, W. Y. Wu, T. W. Chen, T. M. Chen, T. T. Lin, J. A. Jiang. “Non-destructive quarantine technique- potential application of using X-ray images to detect early infestations caused by riental fruit fly (Bactrocera dorsalis)(Diptera: Tephritidae) in fruit.” Formosan Entomologist Vol. 26, pp. 171-186. 2006
[48] 林建成，“應用電腦影像處理技術輔助X光行李貨物影像辨識，” 今日海關第76期，財政部關務署，臺北，臺灣 2015年4月
[49] C. C. Lin, F. J. Shiou, “Object recognition based on foreground detection using X-ray imaging,” Journal of the Chinese Institute of Engineers,” Vol. 41, pp. 1-8 2018
[50] M. H. Korayem, R. Mahmudi, W. J. Poole, “Enhanced properties of Mg-based nano-composites reinforced with Al2O3 nano-particles,” Materials Science and Engineering A, Vol. 519, pp. 198-203, 2009.
[51] S. F. Hassan, M. Gupta, “Effect of particulate size of Al2O3 reinforcement on microstructure and mechanical behavior of solidification processed elemental Mg,” Journal of Alloys and Compounds, Vol. 419, pp. 84-90, 2006
[52] M. Paramsothy, S.F. Hassan, N. Srikanth, M. Gupta, “Enhancing tensile/compressive response of magnesium alloy AZ31 by integrating with Al2O3 nanoparticles, ” Materials Science and Engineering A, Vol. 527, pp. 162-168, 2009
[53] M. Paramsothy, Q. B. Nguyen, K. S. Tun, J. Chan, R. Kwok, J. V. M. Kuma, M. Gupta, “Mechanical property retention in remelted microparticle to nanoparticle AZ31/Al2O3 composites,” Journal of Alloys and Compounds, Vol. 506, pp. 600-606, 2010
[54] 黃政揚, “WS2無機奈米管對鎂合金複合材料的機械性質與微觀組織影響之研究,” 國立臺灣科技大學機械工程學系碩士論文, 2015.
[55] 黃建忠, “強化相粒徑對AZ61/SiCp鎂基複合材料鑄錠及擠型材之機械性質影響的研究,” 國立臺灣科技大學機械工程學系碩士論文, 2013.
[56] 吳懿璋, “強化相粒徑與含量對AZ61/SiCp鎂合金複合材料於擠製加工及後續退火製程在機械性質影響之研究,” 國立臺灣科技大學機械工程學系碩士論文, 2014.
[57] 何佳翰, “AZ31/SiCp鎂基複合材料擠製板材之機械性質與成形性影響之探討,” 國立臺灣科技大學機械工程學系碩士論文, 2014.
[58] R. Z. Valiev, R. K. Islamgaliev, I. V. Alexandrov, “Bulk nanostructured materials from severe plastic deformation,” Progress in Materials Science, Vol. 45, pp.103-189, 2000
[59] Y. Iwahashi, J. Wang, Z. Horita, M. Nemoto, T. G. Langdon, “Principle of equal-channel angular pressing for the processing of ultra-fine grained materials,” Scripta Materialia, Vol. 35, pp. 143-146. 1996
[60] F. J. Humphreys, M. Hatherly, “Recrystallization and related annealing phenomena,” Amsterdam; Boston: Elsevier , pp. 431-432, 2004
[61] T. Mukai, H. Watanabe, K. Higashi, “Grain refinement of commercial magnesium alloys for high-strain-rate-superplastic forming,” Materials Science Forum, Vol. 350-351, pp. 159-170. 2000
[62] K. Furuno, H. Akamatsu, K. Oh-ishi, M. Furukawa, Z. Horita, T. G. Langdon, “Microstructural development in equal-channel angular pressing using a 60° die,” Acta Materialia, Vol. 52, pp. 2497-2507. 2004
[63] B. D. Cullity, S. R. Stock, Elements of X-ray diffraction, Prenticeey Hall. Upper saddle river, New Jersey , pp. 11-12, 2001
[64] 御園生圭輔等著,李明憲譯, “ X光線診斷學”,大學圖書,1969
[65] 行政院原子能源委員會，Atomic Energy Council, 2015, 網站: https://www.aec.gov.tw/
[66] G. Taguchi, System of experimental design: engineering methods to optimize quality and minimize costs, Vol. 1, UNIPUB, 1987
[67] 李輝煌，田口方法：品質設計的原理與實務，第四版，臺北：高立圖書，2013。
[68] R. Laganiere, “OpenCV 2 Computer Vision Application Programming Cookbook.” Packt Publishing Limited, 31 May 2011
[69] G. Bradski, A. Kaehler. “Learning OpenCV: Computer Vision with the OpenCV Library.” O’REILLY, United States of America, 2008
[70] 鍾國亮，“影像處理與電腦視覺”，東華書局，2006。
[71] A. Zak, L. S. Ecker, R. Efrati, L. Drangai, N. Fleischer, R. Tenne, “Large-scale Synthesis of WS2 Multiwall Nanotubes and their Dispersion, an Update,” Sensors & Transducers Journal, Vol. 12, pp. 1-10, 2011.
[72] F. Wang, I. A. Kinloch, D. Wolverson, R. Tenne, A. Zak, E. O'Connell, U. Bangert, R. J. Young, “Strain-induced phonon shifts in tungsten disulfide nanoplatelets and nanotubes.” 2D Materials Vol. 4, No 1, 015007, pp. 1-14, 2016
[73] Y. Iwahashi, Z. Horita, M. Nemoto, T. G. Langdon, “The Process of Grain Refinement in Equal-Channel Angular Pressing,” Acta Meterialia, Vol. 46, pp. 3317-3331, 1998