Theoretical and Experimental Study of Micro- and Nano-Forming of Metal Alloys

• Main Authors: Cheng-Da Wu, 吳政達
• Other Authors: Quang-Cherng Hsu
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/19431858856313959682

碩士 === 國立高雄應用科技大學 === 機械與精密工程研究所 === 92 === This thesis aims at the theoretical and experimental study for Micro- and Nano-forming of metal alloys. The study consists of three parts, namely, molecular dynamics analysis, finite element analysis, and micro forming experiment. In the theoretical stage, simulation codes based on molecular dynamics method were developed to understand the mechanism and behavior of nanoimprint process for Cu/Ni metal alloy. Several process parameters were analyzed, such as the critical width of punch, forming temperature, imprinting velocity, taper angle, spring back and potential energy mode. A commercial finite element code, DEFORM, was also used to study the micro forming process for Cu/Ni metal alloy, such as to understand the temperature effect, velocity effect and forming height. Material properties for DEFORM analysis such as constant shear friction factor and stress-strain relationship are obtained from ring compression test. In the experimental part, process parameters of micro forming for Cu/Ni metal alloy, such as the forming load-displacement relations and forming heights of micro parts, are obtained. A nickel based die (SKD 61) with micro features was used to deform Cu/Ni metal alloy at several different temperatures, which was manufactured by electrical discharge machining. Finally, the results of the simulations including molecular dynamics method and finite element method were compared with the experimental data, for example the relationship between loading and displacement, pattern contour after unloading. These results on one hand can prove the suitable simulation schemes, and on the others, it helps us to clarify the size effects of Micro- and Nano-forming.