電磁力抑制圓管複材鑽孔脫層探討

隨著科技的發展，新一代的複合材料不只應用於航太工業，也漸漸融入一般生活產品中，像是汽車與腳踏車的結構多有使用碳纖維材料等。複合材料除了比傳統單一材料如金屬有更強的機械性質，其優點還包括依照需求來設計相應的材料，換句話說能依照產品的設計來製造符合需求的材料，不需要屈就於材料的性質來改變設計，也正是因為這些優點使的複材的應用不斷增加。鑽孔，是最常見的機械加工之一，在工件上製造孔洞做為組裝接合之用。複材的應用，也需要進行鑽孔加工。由於複材並非單一材料，而是由不同材料組合而成，在進行鑽孔時，往往會在出口前最後一層有層跟層之間的分離，稱之為脫層。脫層的產生無疑地也造成複材機械性質的下降，也因此諸多學者提出了方法來改善脫層，本文介紹的是一種改善非平面(管材)複材鑽孔脫層的方法。為了改善非平面複材鑽孔的脫層，設想使用具流動性的導磁性膠體，引發產生磁力來增加非平面複材所能承受的臨界推力，進而減小脫層的面積，改善加工品質。實驗中設計了電磁鐵來吸引導磁性膠體產生磁力，並使用常見的麻花讚來進行鑽孔，以進給速率、供給電流大小以及鐵粉體積濃度作為實驗參數，討論三者對加工過程的影響。實驗結果顯示，脫層隨進給速率增加，增強電磁場能抑制脫層，鐵粉體積濃度存在抑制脫層之最佳值，並非鐵粉體積濃度越高效果越好，使用特定鐵粉體積濃度約24%的膠體，具有最好的加工效果。

關鍵字

複合材料鑽孔；複材鑽孔脫層；複合材料圓管；電磁力

並列摘要

Drilling is the most frequently used machining method on composite material for the need of structure joint, which often causes delamination at the exit of composite drilling. Delamination is one of the major problems of composite drilling, will reduce the mechanical strength of composite material. For increasing usage of composite material in aerospace and automobile, such as Boeing787 or Tesla electrical vehicle, delamination is not only mechanical problem but safety concern. Therefore, reducing delamination is an important issue for composite machining. There are several methods for flat composite material to reduce delamination during drilling but few for curved surface. This study proposes an idea using electromagnet and colloid mixed with iron powder to produce magnetic back-up force and reduce delamination at exit of composite drilling. The experimental parameters include feed rate, current, and iron powder volume concentration. The result shows that delamination area grows with increasing feed rate and reduced electrical current. It also finds that there is an optimal value for iron powder volume concentration of about 24% in this method.

並列關鍵字

composite drilling ； delamination ； composite tube ； electromagnet force

參考文獻

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[9] S. Jain, and D. C. Yang, “Effects of Feed Rate and Chisel Edge on Delamination in Composite Drilling”, ASME, Journal of Engineering for Industry, Vol. 115, pp.398-405(1993)

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電磁力抑制圓管複材鑽孔脫層探討

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