Effects of Harmonic Vibrations of Cutting Speed on Cutting Force and Surface Quality in Al 7075-T6 Broaching

摘要

Broaching is a single-pass machining operation for producing complex profiles with finished surface qualities, which is mostly used in mass production where short manufacturing lead-time is desired. Despite its importance in machining industry, broaching received little attention in academic studies after emergence of high-speed CNC machines. The present study was carried out in two phases with the aim of enhancing surface quality and lowering cutting force in broaching of Al 7075-T6. In the first phase, broaching tests were performed with four constant cutting speeds (5, 10, 15, and 20 m/min). In the second phase of the experimentation, harmonic vibrations (dithers) with tailored amplitude and frequency were intentionally added to the cutting speed in order to investigate the effects on the process performance. In this phase, the tests were conducted with two different cutting speeds (5 and 10 m/min). All the experiments were performed using a servo hydraulic system with position and speed control. Results reveal that increasing the cutting speed and applying dither, not only enhance surface quality but also lower the cutting force. The results of this study can be applied to achieve higher productivity with lower cost in a modern industrial setting.