本論文主要探討"尺寸效應(Size Effect)"對於微金屬成形製程之影響，並透過傳統有限元素模擬程式進行分析，以了解微成形與傳統成形之差異，並且提出超音波輔助應用於微成形加工之概念，希望藉此改善尺寸效應對於微成形製程之影響。
　　本論文首先進行微拉伸試驗，以不同熱處理溫度改善試片內部之晶粒尺寸與大小，並搭配兩種不同尺寸之試片進行試驗，比較所有試片之應力應變曲線，發現晶粒尺寸以及幾何外形皆會影響試片應力應變曲線之大小。
　　本論文亦進行有限元素分析程式模擬微伸張成形製程(Micro Stretching Process)，並與實驗之最大負荷與破裂衝程等結果相互比較，發現傳統有限元素分析程式之模擬極限為厚度0.1mm，之後隨著厚度變薄，表層晶粒與試片截面積之比值增加，則模擬與實驗之誤差也隨之加大。
　　最後提出超音波振動輔助加工之概念，將超音波振動加載於L形微彎曲製程與微深引伸製程，並選用不同之振幅條件，以超音波振動造成試片表面產生加工硬化之效果，降低L形微彎曲成形過程因材料彈性回復造成的回彈現象(Springback)，並且發現強度越低之材料，在超音波振動之條件下，其回彈角度之改善越明顯。而超音波振動加載於微深引伸成形製程，可有效降低試片與模壁間之摩擦力，如此可明顯的降低成形負荷並增加材料之極限引伸比(Limit Drawing Ratio)，且由於與模壁間之摩擦力降低，成形後之圓杯壁厚也較為均勻一致。
　　本論文針對尺寸效應對於材料機械性質與三種不同微成形製程之影響，分別進行研究與分析，並藉由實驗所得之結果與驗證，描述尺寸效應於微製程中可能產生之影響，並提出超音波輔助之概念，以期能夠以此結果提供日後研究微成形製程之參考。

This research focused on the influence of size effect during micro-metal forming processes and attempted to understand the difference between macro and micro forming processes by finite element program simulation. In order to solve these influences from size effect, this research also presented a concept of ultrasonic assistance on micro forming processes.
Firstly, this research conducted a micro tensile test for variable thicknesses of copper foil. Heat treatment process had been used for generating different grain size on each thickness. And two different shapes of specimen were also chosen for this test. Then the relationship between the decreasing of flow stress curve and the size effect was found.
Secondly, the finite element program was used for the simulation of micro stretching process. After comparing with the results between the simulation and the experiment, the limitation of this analysis on micro stretching process was determined to be 0.1 mm of specimen thickness.
Finally, this research presented the concept of ultrasonic assistance on micro bending process and micro deep drawing process. Different amplitudes were also chosen for both processes to reduce the springback angle on micro bending process and to reduce the friction force between blank and mother die on micro deep drawing process. The limit drawing ratio also increased and the wrinkle effect was restrained with applying ultrasonic vibration on micro deep drawing process.
This dissertation conducted three different micro forming processes to find the influences of size effect on each process and present a concept of ultrasonic assistance on micro forming processes. All results and conclusions in this dissertation could be the reference for further researches and the micro product fabrication.

1. Geiger, M., Kleiner, M., et al., "Microforming." , CIRP Annals - Manufacturing Technology Vol.50, Issue2, pp. 445-462 (2001)
2. Engel, U. and Eckstein, R., "Microforming - from basic research to its realization." , Journal of Materials Processing Technology Vol.125-126, pp.35-44 (2002)
3. Vollertsen, F., Biermann, D., et al., "Size effects in manufacturing of metallic components." , CIRP Annals - Manufacturing Technology Vol.58, Issue2, pp.566-587 (2009)
4. Qin, Y., "Micro-forming and miniature manufacturing systems — development needs and perspectives." , Journal of Materials Processing Technology, Vol.177, Issue1-3, pp.8-18 (2006)
5. Armstrong, R. W., "On size effects in polycrystal plasticity." , Journal of the Mechanics and Physics of Solids, Vol.9, pp.196-199 (1961)
6. Miyazaki, S., Shibata K., et al., "Effect of specimen thickness on mechanical properties of polycrystalline aggregates with various grain sizes." , Acta Metallurgica, Vol.27, Issue 5, pp.855-862 (1979)
7. Raulea, L. V., Goijaerts A. M., et al., "Size effects in the processing of thin metal sheets." , Journal of Materials Processing Technology, Vol.115, Issue 1, pp. 44-48. (2001)
8. Michel, J. F. and Picart, P., "Size effects on the constitutive behavior for brass in sheet metal forming." , Journal of Materials Processing Technology, Vol.141, Issue 3, pp.439-446 (2003)
9. Hoffmann, H. and Hong, S., "Tensile test of very thin sheet metal and determination of flow stress considering the scaling effect." , CIRP Annals - Manufacturing Technology, Vol.55, Issue1, pp.263-266 (2006)
10. Gau, J. T., Principe, C., et al., "An experimental study on size effects on flow stress and formability of aluminum and brass for microforming." , Journal of Materials Processing Technology, Vol.184, Issue1-3, pp.42-46 (2007)
11. Tsai, M. C., Chen, Y. A., et al., "Size-Effects in Micro-Metal Sheet Forming of Unalloyed Copper and Brass." , Advanced Materials Research, Vol.6-8, pp.705-712 (2005)
12. Simons, G., Weippert, C., et al., "Size effects in tensile testing of thin cold rolled and annealed Cu foils." , Materials Science and Engineering, Vol.416, Issue1-2, pp.290-299 (2006)
13. Fu, M. W. and Chan, W. L., "Geometry and grain size effects on the fracture behavior of sheet metal in micro-scale plastic deformation." , Materials & Design, Vol.32, Issue10, pp.4738-4746 (2011)
14. Geisdorfer, S., Engel, U., et al., "FE-simulation of microforming processes applying a mesoscopic model." , International Journal of Machine Tools and Manufacture, Vol.46, Issue11, pp.1222-1226 (2006)
15. Geiger, M., Geisdorfer, S., et al., "Mesoscopic model: advanced simulation of microforming processes." , Production Engineering, Vol.1, Issue1, pp.79-84 (2007)
16. Stolken, J. S. and Evans, A. G., "A microbend test method for measuring the plasticity length scale." Acta Materialia, Vol.46, Issue14, pp.5109-5115 (1998)
17. Shrotriya, P., Allameh, S. M., et al., "On the measurement of the plasticity length scale parameter in LIGA nickel foils." , Mechanics of Materials, Vol.35, Issue3-6, pp.233-243 (2003)
18. Li, L., Zhou, Q., et al., "Numerical study on the size effect in the ultra-thin sheet's micro-bending forming process." , Materials Science and Engineering: A , Vol.499, Issue1-2, pp.32-35 (2009)
19. Suzuki, K., Matsuki, Y., et al., "Tensile and microbend tests of pure aluminum foils with different thicknesses." , Materials Science and Engineering: A, Vol.513-514, pp.77-82 (2009)
20. Gau, J. T., Principe, C., et al., "Springback behavior of brass in micro sheet forming." , Journal of Materials Processing Technology, Vol.191, Issue1-3, pp.7-10 (2007)
21. Shan, D. B., Wang, C. J., et al., "Effect of thickness and grain size on material behavior in micro-bending." , Transactions of Nonferrous Metals Society of China, Vol.19, pp.507-510 (2009)
22. Liu, J. G., Fu, M. W., et al., "Influence of size effect on the springback of sheet metal foils in micro-bending." , Computational Materials Science, Vol.50, Issue9, pp.2604-2614 (2011)
23. Li, H., Dong, X., et al., "Size effect on springback behavior due to plastic strain gradient hardening in microbending process of pure aluminum foils." , Materials Science and Engineering: A, Vol.527, Issue16-17, pp.4497-4504 (2010)
24. Hezong, L., Xianghuai, D., et al., "Determination of material intrinsic length and strain gradient hardening in microbending process." , International Journal of Solids and Structures, Vol.48, Issue1, pp.163-174 (2011)
25. Li, H., Dong, X., et al., "Analysis of microbending of CuZn37 brass foils based on strain gradient hardening models." , Journal of Materials Processing Technology, Vol.212, Issue3, pp.653-661 (2012)
26. Saotome, Y., Yasuda, K., et al., "Microdeep drawability of very thin sheet steels." , Journal of Materials Processing Technology, Vol.113, Issue1-3, pp.641-647 (2001)
27. Marumo, Y., Saiki, H., et al., "Effect of sheet thickness on deep drawing of metal foils." , Journal of Achievements in Materials and Manufacturing Engineering, Vol.20, Issue1-2, pp.479-482 (2007)
28. Wang, C. J., Guo, B., et al., "Effect of die cavity dimension on micro U deepdrawing behaviour with T2 foil." , Transactions of Nonferrous Metals Society of China, Vol.19, pp.790-794 (2009)
29. Vollertsen, F. and Hu, Z., "Analysis of punch velocity dependent process window in micro deep drawing." , Production Engineering, Vol.4, Issue6, pp.553-559 (2010)
30. Chen, C. H., Gau, J. T., et al., "An Experimental and Analytical Study on the Limit Drawing Ratio of Stainless Steel 304 Foils for Microsheet Forming." , Materials and Manufacturing Processes, Vol.24, Issue12, pp.1256-1265 (2009)
31. Chen, C. H., Lee, R. S., et al., "Size effect and forming-limit strain prediction for microscale sheet metal forming of stainless steel 304." , Journal of Strain Analysis for Engineering Design, Vol.45, Issue4, pp.283-299 (2010)
32. Witulski, N., Justinger, H, Hirt, G., "Validation Of FEM-Simulation For Micro Deep Drawing Process Modeling." , Proceedings of the 8th International Conference on Numerical Methods in Industrial Forming Processes, AIP Conference Proceedings, Vol.712, pp.952-957 (2004).
33. Justinger, H. and Hirt, G., "Estimation of grain size and grain orientation influence in microforming processes by Taylor factor considerations." , Journal of Materials Processing Technology, Vol.209, Issue4, pp.2111-2121 (2009)
34. Manabe, K., Shimizu, T., et al., "Validation of FE simulation based on surface roughness model in micro-deep drawing." , Journal of Materials Processing Technology, Vol.204, Issue1-3, pp.89-93 (2008)
35. Ku, T. W., Hwang, S. M., et al., "Milli-component forming of rectangular cup drawing." , Journal of Materials Processing Technology, Vol.113, Issue, 1-3, pp.749-753 (2001)
36. Shim, H. B., "Improving formability to develop miniature stamping technologies." , International Journal of Precision Engineering and Manufacturing, Vol.10, Issue2, pp.117-125 (2009)
37. Gong, F., Guo, B., et al., "Micro deep drawing of micro cups by using DLC film coated blank holders and dies." , Diamond and Related Materials, Vol.20, Issue2, 196-200 (2011)
38. Hu, Z., Schubnov, A., et al., "Tribological behaviour of DLC-films and their application in micro deep drawing." , Journal of Materials Processing Technology, Vol.212, Issue3, pp.647-652 (2012)
39. Marumo, Y., Saiki, H., et al., "Effects of lap sheets on the improvement of the formability of metal foil." , Journal of Materials Processing Technology , Vol.113, Issue1-3, pp. 627-631 (2001)
40. Pasierb, A. and Wojnar, A., "An experimental investigation of deep drawing and drawing processes of thin - walled products with utilization of ultrasonic vibrations." , Journal of Materials Processing Technology, Vol.34, Issue1-4, pp.489-494 (1992)
41. Jimma, T., Kasuga, Y., et al., "An application of ultrasonic vibration to the deep drawing process." , Journal of Materials Processing Technology, Vol.80-81, pp.406-412 (1998)
42. Siegert, K. and Ulmer, J., "Influencing the Friction in Metal Forming Processes by Superimposing Ultrasonic Waves." , CIRP Annals - Manufacturing Technology, Vol.50, Issue1, pp.195-200 (2001)
43. Ashida, Y. and Aoyama, H., "Press forming using ultrasonic vibration." , Journal of Materials Processing Technology, Vol.187-188, pp.118-122 (2007)
44. Tsujino, J., Ueoka, T., et al., "Ultrasonic vibration bending of metal plate specimens." , ULTRASONICS SYMPOSIUM, Vol.2, pp.1099-1102 (1989)
45. Mousavi, S. A. A. A., Feizi, H., et al., "Investigations on the effects of ultrasonic vibrations in the extrusion process." , Journal of Materials Processing Technology, Vol.187-188, pp. 657-661 (2007)
46. Bunget, C. and Ngaile, G., "Influence of ultrasonic vibration on micro-extrusion." , Ultrasonics, Vol.51, Issue5, pp.606-616 (2011)
47. ASTM, 2004,”ASTM E8M”, ASTM Std.
48. ASTM, 2004,”ASTM E112” ASTM Std.
49. ASTM, 2002,”ASTM E345” ASTM Std.