晶粒尺寸效應在微管件擴孔極限之研究

近年來因產品的微小化趨勢，微型化技術已被廣泛使用於各個領域，其中微管件(Micro-Tube)為重要的微元件之一，但針對微管件於製造過程中易於引起的破壞模式的研究還很少，故本文目的為探討微管件的機械行為變化，如破裂、頸縮、彎曲、挫曲等塑性變化現象。本研究中採用不同壁厚(0.15、0.3、0.45與0.6 mm)的SUS 304不鏽鋼微管件，利用拉伸試驗瞭解其管件機械性質，並藉由自行組裝微擴孔成型平臺進行擴孔試驗探討微管件擴孔極限，擴孔試驗使用不同衝頭角度(30、45與60°)來研究衝頭角度對微管件擴孔極限的影響，此外，並將微管件進行不同溫度(950、1000、1050°C)退火熱處理，研究晶粒變化對微管件機械行為的影響。同時使用電腦輔助有限元素分析軟體(Marc)進行模擬，從中獲得微管件擴孔衝程參數並與實驗結果進行比對，由實驗結果可以得知，衝頭角度越大相對反作用力越大，而退火熱處理後管件擴孔極限較大，從模擬中所得到之管件擴孔極限與實驗結果相符。

關鍵字

微成型；退火熱處理；晶粒尺寸效應；擴孔極限

並列摘要

Owing to the miniaturization tendency of products, “Micro-forming” is widely used in various fields. Especially micro-tube is a kind of micro-parts, however, the researches in failure mechanism is still not clear. The objective of this study is to investigate the behavior of plastic deformation of micro-tube, such as fracture, necking, bending and buckling. Stainless steel SUS-304 is used in the experiments. Tube thickness is 0.15, 0.3, 0.45 and 0.6 mm respectively. Firstly, to ensure the mechanical properties of SUS-304 tube, tensile test was carried out. Secondly, flaring tests executed by micro flaring test system was employed to investigate the flaring limit. Flaring tests was performed with different conical tool angles (30,45,60°) to study the effect of conical tool angles on flaring limit. In addition, the grain size effect on micro-tube was investigated by using the tubes with annealing treatment. Furthermore, FEA (Finite Element Analysis) simulations were also carried out to compare with experimental results. According to the results of flaring tests, reaction force increased as the conical tool angles increased; the tubes after annealing treatment can reach larger flaring limit. Consequently, the simulation results have a good agreement with experimental results.

並列關鍵字

Micro-Forming ； Annealing Treatment ； Grain Size Effect ； Flaring Limit

參考文獻

2 Yung-Hwa Lu*, “Study of tube flaring ratio and strain rate in the tube flaring process,” Finite elements in analysis and design 40, pp.305-318, 2004.

3 You.-Ming. Huang, “Finite element analysis of tube flaring process with a conical tool,” Manuf Technol 24, pp.91-97, 2004.

4 M.L. Alves, “End forming of thin-walled tubes,” Journal of Materials Processing Technology 177, pp.183-187, 2006.

5 M.A. Mirzai, “Deformation Characteristics Of Microtubes In Flaring Test,” Materials and Processing Technologies, pp510-519, 2007.

6 M. Geiger, “Fundamentals on the Manufacturing of Sheet Metal Microparts,” Fertigungstechnologie, 1996.

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晶粒尺寸效應在微管件擴孔極限之研究

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