本研究為探討摩擦攪拌點銲製程中，其銲道區域內的材料流動模式。利用在銲接前在上下鋁板埋入粉末，並且使用不同製程參數及幾何形狀的工具，追蹤點銲過程中材料流動的軌跡，以了解銲道材料流動情形。另外使用不同工具肩部角度之工具做FSSW製程，去觀察不同工具其建立的暫態拘束空間(Transient Constrain Space)對銲道形貌的影響，藉此進一步了解不同工具肩部影響材料流動的機制。
實驗結果顯示，在銲件尚未建立暫態拘束空間時，上下板材料不會因為製程時間的增長促使上下板材料流動結合，使銲件得到良好的攪拌區；而觀察已建立暫態拘束空間的銲件中，從不同銲接秒數銲件的縱斷面及水平橫斷面發現，圓柱有牙的工具銷其促使材料進入銷內攪拌的單一流入口處為螺牙起始處，而三角無牙的工具銷是利用其工具上的側平面推擠，形成一波紋狀的材料流動情形，並且材料進入到攪拌銷內有多重流入口；同一幾何不同工具肩部角度，將會影響銲件內暫態拘束空間其拘束空間材料的流動能力，影響銲件的上板有效厚度、攪拌區發展及銲件兩板界面(Interface)幾何形狀的形成，因而改變銲件的拉剪強度。

In this thesis, the development of material flow during friction stir spot welding (FSSW) are discussed. The experimental were divided into two parts. In the first part of the study, tracing powders were embedded into the welding sheets to investigate material flowing behaviors during FSSW, FSSW at a tool speed of 2500 rpm, with a plunging rate of 1 mm/s, and dwell time of 0s、2s and 4s. In the second part of the study, those are a cylindrical pin with threads and a triangular pin without threads, were used to determine the geometric effects on FSSW.
Experimental results show that without established TCS, the desired mechanical properties of Al alloy A6061-T6 welds could not be obtained. In addition, the welds using the cylindrical pin with threads and shoulder-angle of 13 degree exhibited the largest elongation and highest tensile strength. A new model of material flow was proposed with the schematic diagrams to illustrate the differences caused by tool geometries, and it would be beneficial for further design of welding tools in the future.

1. 劉文海，『鋁合金車體及底盤之發展動向』，機械工業雜誌281期，民國95年8月，75-89頁。
2. Fonda, R. W., Bingert, J. F., “Colligan, K. J., ”Development of grain structure during friction stir welding”, Sripta Materialia, Vol. 51, pp. 243-248 (2004).
3. Deqing, W., Shuhua, L., “Study of friction stir welding of aluminum”, Journal of Materials Science, Vol. 39, pp. 1689-1693 (2004).
4. Mishra, R. S., Ma, Z. Y., “Friction stir welding and processing”, Mater. Sci. Eng., R, Vol. R50, pp. 1–78 (2005).
5. Sanders, D. G., Ramulu M., Edwards, P. D.,” Superplastic Forming of Friction-Stir Welds in Titanium Alloy 6Al-4V: Preliminary Results“, Materialwissen shaft und We-kstofflechnik, 39, pp. 553–557(2008).
6. J. F. Hinrichs, C. B. Smith, B. F. Orsini, R. J. DeGeorge, B. J. Smale, ”Friction Stir Welding for the 21st Century Automotive Industry”, Friction Stir Link, Inc. Waukesha, USA.
7. http://www.twi.co.uk/
8. Badarinarayan, H., Yang, Q., Zhu, S., “Effect of tool geometry on static strength of friction stir spot-welded aluminum alloy”, International Journal of Machine Tools & Manufacture, 49, pp. 142–148 (2009).
9. D.H. Choi , C.Y. Lee , B.W. Ahn , “Frictional wear evaluation of WC–Co alloy tool in friction stir spot welding of low carbon steel plates“, International Journal of Refractory Metals & Hard Materials, 27,pp.931-936(2009).
10. S. Bozzi, A.L. Helbert-Etter, T. Baudin, B. Criqui, J.G. Kerbiguet, ”Intermetallic compounds in Al 6016/IF-steel friction stir spot welds” Materials Science and Engineering A 527, pp.4505–4509 (2010).
11. Shigeki Hirasawa, Harsha Badarinarayan, ”Analysis of effect of tool geometry on plastic flow during friction stir spot welding using particle method” Journal of Materials Processing Technology,(2010).
12. http://www.twi.co.uk/
13. Lin, B. Y., Liu, J. J., Lu, L. D. and Tsai, H. L., “Effect of Root Flaw on Tensile Behavior of Friction Stir Welded A6061-T6 Aluminum Alloy”, Advanced Materials Research, Vols. 482-484, pp. 1343-1349 (2012).
14. Joel, J D. "The Friction Stir Welding advantage" , Welding Journal, Vol. 80, No. 5, pp. 269-273 (2001).
15. Horie, S., Shinozaki, K., Yamamoto, M., Kadoi, K., North, T.H., “Effects of tool geometry and process conditions on material flow and strength of friction stir spot welded joint”, 日本溶接學會論文集, 第29卷, 第3號, pp. 119s-123s (2011).
16. Yin, Y. H., Sun, N., North, T. H., Hu, S.S., “Microstructures and mechanical properties in dissimilar AZ91/AZ31 spot welds”, Materials Characterization, 6 1, pp. 1018-1028 (2010).
17. Tozakia, Y., Uematsub, Y., Tokaji, K., “Effect of tool geometry on microstructure and static strength in friction stir spot welded aluminium alloys”, International Journal of Machine Tools & Manufacture, 47, pp. 2230–2236 (2007).
18. Fatini, L., Barcellona, A., Buffa, G., Palmeri, D., “Friction stir spot welding of AA6082-T6: influence of the most relevant process parameters and comparison with classic mechanical fastening techniques”, Proc. IMechE, Vol. 221 part B, J. Engineering Manufacture, pp. 1111-1118 (2007).
19. Yuana, W., Mishra, R., Webb, S. S., Chen, Y. L, Carlson, B., Herling, D. R., Grant, G. J., “Effect of tool design and process parameters on properties of Al alloy 6016 friction stir spot welds”, Journal of Materials Processing Technology, 211, pp. 972–977 (2011).
20. Arul, S. G., Miller, S. F., Kruger, G. H., Pan, T. Y., Mallick, P. K., Shih, A. J., “Experimental study of joint performance in spot friction welding of 6111-T4 aluminium alloy”, Science and Technology of Welding and Joining, Vol. 13, NO 7, pp. 629 (2008).
21. Bozzi, S., Helbert-Ettera, A.L., Baudin, T., Klosek, V., Kerbiguet, J.G., Criqui, B., “Influence of FSSWparameters on fracture mechanisms of 5182 aluminium welds”, Journal of Materials Processing Technology , 210, pp. 1429–1435 (2010).
22. Horie, S., Yamamoto, M., Shinozaki, K., North, T. H., Kadoi, K., Gerlich, A., Shibayanagi, T., “Local Melting and Cracking during Friction Stir Spot welding on Mg-Al binary alloy”, 日本溶接學會論文集, 第27卷第2號, pp. 94s-98s (2009).
23. Lathabai, S., Painter, M. J., Cantin G. M. D. and Tyagi, V.K., “Friction spot joining of an extruded Al–Mg–Si alloy”, Scripta Materialia, 55, pp. 899–902 (2006).
24. Yin, Y. H., Ikuta, A., North, T. H., “Microstructural features and mechanical properties of AM60 and AZ31 friction stir spot weld”, Mater Des, 31, pp. 4764–4776 (2010).
25. Fujimoto, M., Watanabe, Abe, D., N., Yutaka, S. S., Kokawa, H., “Effects of process time and thread on tensile shear strength of Al alloy lap joint produced by friction stir spot welding”, Welding Int., Vol. 24, No.3, March, pp. 169-175 (2010).
26. Tozaki, Y., Uematsu, Y., Tokaji, K., “A newly developed tool without probe for friction stir spot welding and its performance”, Journal of Materials Processing Technology , 210, pp. 844–851 (2010).
27. 刘克文, 邢丽, 柯黎明, “LY12铝合金摩擦搅拌点焊接组织及性能”, The Chinese Journal of Nonferrous Metals, 第18卷,第2期, pp. 288-293 (2008).
28. Yoshihiko, Kiero, T., Yasunari, T., Tatsuo, K., Shunsuke, M., “Effect of post heat treatment on fatigue behavior of friction stir spot welded Al-Mg-Si alloy”, 溶接學會論文集 第26卷第1號, pp. 7-14 (2009).
29. Yuana, W., Mishra, R., Webb, S. S., Chen, Y. L, Carlson, B., Herling, D. R., Grant, G. J., “Effect of tool design and process parameters on properties of Al alloy 6016 friction stir spot welds”, Journal of Materials Processing Technology, 211, pp. 972–977 (2011).
30. Bakavos, D., Chen, Y., Babout, L., Prangnell, P., “Material interactions in a novel pinless tool approach to friction stir spot welding thin aluminum sheet”, Metallurgical and materials transactions A, Vol 42A, MAY, pp. 1266-128(2011)2.
31. Fujimoto, M., Koga, S., Abe, N., Sato, S. Y., Kokawa, H., “Analysis of plastic flow of thte Al alloy joint produced by friction stir spot welding”, Welding International, Vol. 23, No. 8, 589-596 (2009).
32. Su, P., Gerlich, A., North, T. H., and Bendzsak, G. J., “Intermixing in Dissimilar Friction Stir Spot Welds”, Metallurgical and materials transactions A, Vol 38a, March, pp. 584-595 (2007).
33. Horie, S., Shinozaki, K., Yamamoto, M. and North, T. H., “Experimental investigation of material flow during friction stir spot welding, Science and Technology of Welding and Joining”, Vol. 15, No. 8, pp. 667-670 (2010).
34. Yang, Q., Mironov, S., Sato, Y. S., Okamoto, K., “Material flow during friction stir spot welding”, Materials Science and Engineering A, 527, pp. 4389–4398 (2010).
35. Yin, Y. H., Sun, N., North, T. H., Hu, S.S., “Microstructures and mechanical properties in dissimilar AZ91/AZ31 spot welds”, Materials Characterization, 6 1, pp. 1018-1028 (2010).
36. 劉如真, “鋁合金A6061-T6摩擦攪拌點銲接合機構之研究“國立台灣科技大學,2012.
37. Yin, Y. H., Sun, N, North, T. H., Hu S. S., “Hook formation and mechanical properties in AZ31 friction stir spot welds”, J. Mater Process Technol, 210, pp. 2062–2070 (2010).
38. Badarinarayan, H., Shi, Y., Li, X., Okamoto, K., “Effect of tool geometry on hook formation and static strength of friction stir spot welded aluminum 5754-O sheets”, International Journal of Machine Tools & Manufacture, 49, pp. 814–823 (2009).
39. 姜志華, “鋁合金電弧銲接及硬軟銲應用技術“,科學圖書大庫,1995.
40. 藤本光生，古賀信次，阿倍奈津美，佐藤裕，粉川博之，”摩擦攪拌点接合で得られた6061 アルミニウム合金攪拌領域の組織学的検討”， 日本溶接学会論文集，第25 巻，第４号，pp. 553-559 (2007)
41. Y. Tozaki, Y.uematsu, K. Tokaji, “Effect of processing parameters on static strength of dissimilar friction stir spot welds between different aluminium alloys”, Fatigue Fract Engng Mater Struct, 30 , pp. 143–148 (2007)