Experimental and modeling study on cutting forces of feed direction ultrasonic vibration-assisted milling

An ultrasonic vibration-assisted milling experiment was made for studying the cutting forces. The experimental results showed that small fluctuations caused by vibration of milling machine and cutting fluid system were restrained after exerting ultrasonic vibration. Horizontal force was used for analyzing the effect of exerted ultrasonic vibration on milling forces. And for ultrasonic vibration with different amplitudes, the horizontal cutting force firstly increases and then decreases. An ultrasonic vibration-assisted milling cutting mechanism model was made in this paper to compute the cutting forces of tangential, radial, and axial directions. A cutting force model was made and it showed that all the three direction forces are influenced by the feed speed, vibration amplitude, and the ratio between vibration frequency and the rotation speed. Air cutting takes place every vibration period when certain relationship was reached. Tangential force is the vector addition of X and Y direction forces, which are the combinations of a linear part and trigonometric parts affected by rotation speed and vibration frequency, respectively. Z direction force changes proportionally to the tangential force. The results indicate that the cutting forces are decreased when feed direction ultrasonic vibration is exerted especially when the feed per tooth is 12 mu m/tooth and the ultrasonic vibration with amplitude 12 mu m is exerted.