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http://dx.doi.org/10.3795/KSME-A.2010.34.10.1463

Investigation on the Size Effects of Polycrystalline Metallic Materials in Microscale Deformation Processes  

Kim, Hong-Seok (Dept. of Mechanical Engineering, Seoul Nat'l Univ. of Technology)
Lee, Yong-Sung (Dept. of Mechanical Engineering, Seoul Nat'l Univ. of Technology)
Publication Information
Transactions of the Korean Society of Mechanical Engineers A / v.34, no.10, 2010 , pp. 1463-1470 More about this Journal
Abstract
Microforming, which exploits the advantages of metal forming technology, appears very promising in manufacturing microparts since it enables the production of parts using various materials at a high production rate, it has high material utilization efficiency, and it facilitates the production of parts with excellent mechanical properties. However, the conventional macroscale forming process cannot be simply scaled down to the micro-scale process on the basis of the extensive results and know-how on the macroscale process. This is because a so-called "size effect" occurs as the part size decreases to the microscale. In this paper, we attempt to develop an effective analytical and experimental modeling technique for explaining the effects of the grain size and the specimen size on the behavior of metals in microscale deformation processes. Copper sheet specimens of different thicknesses were prepared and heat-treated to obtain various grain sizes for the experiments. Tensile tests were conducted to investigate the influence of specimen thickness and grain size on the flow stress of the material. In addition, an analytical model was developed on the basis of phenomenological experimental findings to quantify the effects of the grain size and the specimen size on the flow stress of the material in microscale and macroscale forming.
Keywords
Microforming; Size Effect; Flow Stress; Polycrystalline Material;
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1 Geiger, M., Kleiner, M., Eckstein, R., Tiesler, N. and Engel, U., 2001, “Microforming,” 51st General Assembly of CIRP, Vol. 50(2), pp. 445-462.
2 Engel, U. and Egerer, E., 2002, “Basic Research on Cold and Warm Forging of Microparts,” Key Eng. Mater., Vol. 233-236, pp. 449-455.   DOI
3 Tiesler, N. and Engel, U., 2000, “Microforming-Effects of Miniaturization,” Proceedings of the 8th International Conference on Metal Forming, pp. 355-360.
4 Kals, T. A. and Eckstein, R., 2000, “Miniaturization in Sheet Metal Working,” J. Mater. Process. Technol., Vol. 103, pp. 95-101.   DOI   ScienceOn
5 Messner, A., Engel, U., Kals, R. and Vollersten, F., 1994, “Size Effect in the FE-Simulation of Micro-Forming Processes,” Proceedings of the 5th International Conference on Metal Forming, pp. 371-376.
6 Raulea, L. V., Goijaerts, A. M., Govaert, L. E. and Baaijens, F. P. T., 2001, “Size Effects in the Processing of Thin Metal Sheets,” J. Mater. Process. Technol., Vol. 115, pp. 44-48.   DOI   ScienceOn
7 Kim, G. Y., Koc, M. and Ni, J. “Experimental and Numerical Investigations on Microcoining of Stainless Steel 304,” J. Manuf. Sci. Eng., Vol. 130, Issue 4.
8 Nakamachi, E., Hiraiwa, K., Morimoto, H. and Harimoto, M., 2000, “Elastic/Crystalline Viscoplastic Finite Element Analyses of Single- and Poly-Crystal Sheet Deformations and Their Experimental Verification,” International Journal of Plasticity, Vol. 16, Issue 12, pp. 1419-1441   DOI   ScienceOn
9 Engel, U. and Eckstein, R., 2002, “Microforming-from Basic Research to Its Realization,” J. Mater. Process. Technol., Vol. 125-126, pp. 35-44.   DOI   ScienceOn
10 Peng, L., Lai, X., Lee, H. J., Song, J. H. and Ni, J., 2009, “Analysis of Micro/Mesoscale Sheet Forming Process with Uniform Size Dependent Material Constitutive Model,” Materials Science and Engineering A, Vol. 526, pp. 93-99.   DOI   ScienceOn
11 Kim, G. Y., Ni, J. and Koc, M., 2007, Modeling of the Size Effects on the Behavior of Metals in Microscale Deformation Processes,” J. Manuf. Sci. Eng., Vol. 129, pp. 470-476.   DOI   ScienceOn
12 Hall, E. O., 1951, “Deformation and Ageing of Mild Steel,” Proc. Phys. Soc., Vol. 64, pp. 747-753.   DOI   ScienceOn
13 Petch, N. J., 1953, “Cleavage Strength of Polycrystals,” J. Iron Steel Inst., Vol. 174, pp. 25-28.
14 Fu, H. H., Benson, D. J. and Meyers, M. A., 2001, “Analytical and Computational Description of Effect of Grain Size on Yield Stress of Metals,” Acta Mater., Vol. 49, pp. 2567-2582.   DOI   ScienceOn
15 Cuitino, A. M. and Ortiz, M., “Computational Modeling of Single Crystals,” Modeling and Simulation in Material Sciences and Engineering, Vol. 1, pp. 225-263.