鎂合金管件液壓成形製程參數之建立

A Construction of Process Parameters for Magnesium Alloy Tube Components during Hydroforming

張俊明(Chun-ming Chang)

指導教授 ： 林盛勇

國立虎尾科技大學/工程學院/動力機械工程研究所/碩士(2006年)

https://doi.org/10.6827/NFU.2006.00009

摘要

摘 要
由於鎂合金材料重量輕，深受3C電子業及汽車工業之青睞，但因為鎂合金的成形性很差，在大變形時會呈現負向加工硬化之現象，因此目前其成形皆以熱壓鑄或鎔鑄為主，導致廢料多，成本高。本文之目的為建立一系列鎂合金管件液壓成形的製程參數，以作為工業界鎂合金管件製造之參考。使用AZ31鎂合金管材以液壓方式並輔以機械推力來製作管件。採用有限元素法分析軟體DEFORM-2D/3D解析一些常用管件的成形狀況，包括T型管件、長方形管、直管鼓脹及不規則管的成形等。藉由改變製程參數；諸如沖頭速度、液體壓力、模具-工件界面摩擦係數及模具幾何外型等條件，來探討管件材料之流向、壁厚變化、及應力和應變分佈等，藉由管件最小壁厚合格品之要求及成形可否成功等，綜合分析及研判以建立可製造的製程參數範圍或是最佳之製程條件。結果發現，適宜的機械推力能幫助材料流動，避開大變形時負向加工硬化之區域，以增進鎂合金的成形性，使得管件能順利成形。

關鍵字

製程參數 ； 負向加工硬化 ； 機械推力 ； 液壓成形

並列摘要

Abstract
Due to the light weight and magnetic ray insulation characteristics in magnesium alloy material, it is widely utilized in 3C electronic components and automobile parts. However, its formability is very poor due to the phenomenon of negative rate strain hardening appeared as the deformation in large strain range, so it is usually formed as die casting or casting manner, leads to much scrap and the manufacturing cost is thus increased. The purpose of this study is to construct a series of process parameters for magnesium alloy tube components during hydro-forming and may offer the data resulting from theanalysis as a guideline for magnesium alloy forming in industry. AZ31 magnesium alloy tube is used as the billet for hydro-forming with hydraulic pressure as the main forming power combining with the mechanical auxiliary force to fabricate the tubing products. Finite element software DEFORM-2D/3D is adopted to investigate the forming situations for some in common use fitting tubes, which include T type fitting, rectangle tube, tube bulge forming and irregular tube forming etc.. By changing process parameter, such as punch speed, hydraulic pressure, die-workpiece interface friction and die geometry shape etc. to investigate the material flow of tube fitting, wall thickness variations, and stress and strain distributions. By qualifying the smallest wall thickness of tube fitting requirement and forming sequences completed or not, analysis synthesis and overall judgment to establish an admissible level of process parameter range for complete tube manufacture, or getting optimal process conditions. The results show that suitable mechanical force can help material flow, avoid large strain deformation falling into the area of negative rate strain hardening and enhance magnesium alloy become easy forming, make tube fitting may be formed successfully.

並列關鍵字

process parameters ； negative rate strain hardening ； mechanical force ； hydro-forming

參考文獻

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