複合材料已經廣泛的被應用在航太、機械各大領域中，鑽孔加工是複合材料最常見的加工方式之一；然而此加工方法最大的顧慮在於加工過程出口處產生的脫層現象，脫層對於複合材料的加工品質會造成很大的影響，如何減少脫層現象成為複合材料加工的一項主要課題。
本文提出使用特殊抑制機構的加工方式來改善複合材料脫層的問題，在本實驗中，使用電磁鐵當作施力來源，從鑽孔加工的反向來進行施力，並透過電來控制其電壓及施力大小；以跨距、電壓、進給為變數。由實驗得知，當電壓越大、跨距越小所產生的脫層面積越小，在最佳情況下可以達到50%改善的效果，顯示出本機構的實用性。

Composite materials have been widely used in aerospace and other major mechanical industries. Drilling is among the most common machining operations. The serious concern of drilling is the delamination occurs at exit. How to reduce delamination becomes a major issue in machining composites. This paper presents a way of using special backup to reduce the delamination at exit in drilling composite materials. This experiment used tubular solenoid electromagnet to control the backup force which contributes to suppress the growth of the delamination at drilling exit with parameter backup ratio, voltage, feed rate. The result shows that larger voltage and smaller backup ratio, the delamination area will be smaller. At the best condition a reduction of 50% of delamination area is achieved. It shows that the proposed suppressing mechanism is feasible in practice .

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