Abstract
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 .