Mechanism And Experimental Study On Ultrasonic Vibration Assisted Milling

Milling process is one of the most commonly used metal removal operations in industry. It is based on interrupted cutting which is very susceptible to vibrations. Problems associated with vibrations in machining are more serious when small-diameter end mills are employed. In that case, the tool deformation is prominent and it deteriorates the stability in a machining process. Excessive deflection of a micro end mill may cause tolerance violations and poor surface roughness.Vibration cutting (VC) is a cutting method in which periodical vibration is imposed to the cutting tool or the workpiece, besides the original relative motion between them to obtain better cutting performance. The fundamental feature of VC is that the cutting tool edge is separated from the workpiece repeatedly.Vibration cutting mechanism and experiment results were studied in this paper. Necessary conditions of the cutting tool edge separated from the workpiece repeatedly is proposed for ultrasonic vibration assisted end-milling.One of the necessary conditions for VC, cutting speed should be lower than critical cutting speed, is proposed using vibration planning as an example. VC can increase shear angle and can effectively restrain built up edges.Worktable for ultrasonic vibration assisted cutting was designed in this paper, including vibration generator and logical structure of clamp.The motion track of ultrasonic vibration assisted end-milling cutting edges was investigated, and the motion track of cutting edges was simulited with MATLAB. Necessary conditions of the cutting tool edge separate from the workpiece repeatedly is that the amplitude of ultrasonic vibration should be greater than half of per tooth feed, and cutting length in a tooth cutting period is unequal to integer multiples of ultrasonic vibration wavelength.It is verified by experiment that ultrasonic vibration assisted end-milling can improve workpiece dimensional precision, be beneficial beneficial to chip breaking and decrease cutting force along the vertical feeding direction.