A novel approach to vibratory finishing: Double vibro-polishing

Abstract

ABSTRACTIn most conventional vibratory finishing processes, the vibration flow is in the following order: vibratory motor, machine walls, and ultimately the media which impart finishing action to the components. The components are either freely floating or secured to a fixture in the bulk of media flow throughout the process. Commonly used fixtures are of the mechanical type where components are held on the fixture which is either rigidly bolted to the vibratory finishing machine or freely floating in the media. In this paper, a novel polishing method is introduced: double vibro-polishing. The polishing process deploys a vibratory fixture incorporated in a conventional vibratory finishing setup so that dual vibrations are induced on the components. Ti-6Al-4V workpieces are attached to a vibratory fixture which is immersed in a vibratory finishing trough containing plastic media. Two modes are compared to evaluate asperity changes: vibratory fixture in the “silent” mode which is representative of a mechanical fixture, and the “active” mode giving rise to dual vibro-polishing. Average surface roughness (Ra) is measured using a surface profiler every 15 min until 180 min of process time and the results are plotted. The vibratory fixture demonstrates improvement in the process times in terms of reaching the saturation Ra in a shorter period of time. Force sensors are incorporated onto the fixture to examine the reasons behind the faster finishing.