Real-Time Monitoring of Tool Wear in High-Speed Milling of Aircraft Structural Parts

Aeronautical parts, especially aircraft structures such as landing gear, are usually made of TC18 titanium alloys and other difficult-to-machine materials. The requirements for milling cutters are very high, so the price of cutters is relatively high. However, most of the blanks of aircraft structural parts are made of imported aluminium and titanium alloys, which have high cost. In order to ensure the processing accuracy, the cutting tools have to be replaced frequently. This will cause waste and increase the manufacturing cost because the actual life of the cutting tools is not fully utilized. At the same time, due to the closed high-end CNC milling machine or processing center processing, operators can not observe the actual cutting tool processing situation, can only judge the timing of tool change by experience, can not guarantee the high-quality and efficient processing of parts. So tool wear condition monitoring is a key technology in aircraft structural parts processing. Aiming at the situation that there is no theoretical data to guide tool changing in the process of high efficiency milling of aircraft structural parts, the tool wear monitoring system based on acoustic emission technology is designed according to the characteristics of acoustic emission signal. In this paper, the effects of spindle speed, feed speed, cutting width and tool wear on AE signal are studied by orthogonal experiment. The results show that tool wear has the greatest influence on the signal, followed by spindle speed and feed, and cutting width has the least influence on the signal.