電磁成形技術應用於3C殼件製作之可行性研究

鄭東辰(Tung-Chen Cheng) ； 蘇子可(Tzyy-Ker Sue)

《鍛造》 14卷1期 (2005/04) Pp. 10-15

https://doi.org/10.29791/Forging.200504.0003

摘要

電磁成形為一種利用電磁感應原理，在電磁線圈與待成形金屬胚料之間產生瞬間互斥力，此一互斥力可使金屬胚料產生高速變形，根據研究顯示：金屬（鋁合金）在高應變速率下能呈現比低變形速率下更高的變形能力，此一現象被稱為超塑性(Hyperplasticity)。此外，這種獨特之成形型態還具有以下特色：1.電磁力直接成形工件，因此沒有沖頭只需下模，整體模具結構相當簡單，且模具材料可以使用金屬以外之材質。2.工件以高速撞擊模具時，材料中發生高壓縮應力減少成形時的反彈，可忠實複製模具形狀。
本研究嘗試將電磁成形(Electromagnetic forming)技術應用於3C產業之金屬殼件成形，材料除鋁合金外尚包括難成形之鈦合金（高反彈係數），因此無論就製程技術或材料成形性而言皆為難度頗高之創新應用。本研究希望藉由此項創新製程技術之開發，能有效減少3C殼件的成形道次（降低生產成本）、提高產品尺寸精度（提高產品附加價值），同時在材料選用上及造型設計上賦予產品設計者更大的揮灑空間。
在手機殼件的電磁成形實驗中，本研究針對不同金屬材料進行可行性評估，實驗結果得知純銅擁有最佳之電磁成形性，鋁合金次之；鎂合金成形性最差。

關鍵字

電磁成形 ； 超塑性

並列摘要

The electromagnetic forming (EMF) process relies on a driving force that is induced by eddy current and magnetic field, both of which are generated in the workpiece by a transient current in a nearby coil. Through EMF process, material can be stretched to much higher strains at high velocity versus conventional quasi-static stretching. We refer to this extended ductility in high velocity condition as hyperplasticity.
Comparing with traditional stamping, this process can offer dramatically improved formability, reduce wrinking and active control of spring-back. In this program we will demonstrate the utility of using EMF process to make personal electronics cases from diverse sheet metal. The emphasis will be on improving the surface detail, finish of the parts as well as showing that complex shapes that would normally cause part rupture can be fabricated due to improved high velocity formability.
The results on electromagnetic forming experiment will be reported for: aluminum alloy, copper, titanium and magnesium alloy.

並列關鍵字

Electromagnetic forming ； Hyperplasticity