ORIGINAL ARTICLE Surface motion analysis of double vibro-polishing of Ti-6Al-4 V R. Mediratta 1 & K. Ahluwalia 1 & S. H. Yeo 2 Received: 10 August 2017 / Accepted: 5 February 2018 # Springer-Verlag London Ltd., part of Springer Nature 2018 Abstract Fixturing of workpieces is commonly deployed in vibratory finishing due to the various benefits that this immobilization technique has to offer. The most significant of the benefits is the quality surface finish that can be achieved in shorter process times. Vibratory fixturing is a method where the component is clamped onto a vibrator to induce vibrations to the workpiece. This can accelerate cycle times when incorporated on a vibratory finishing machine. In this work, experiments were conducted using machine and vibratory fixture as the factors influencing the time taken to reach its required average surface roughness of 1 μm. A novel combination of high-speed camera videos and motion analysis software was used to assess the media impact velocities at the media circulating in the machine and thus to elucidate the results obtained in the experimental investigations. Keywords Vibratory polishing . Vibratory fixture . High-speed camera . Media velocity 1 Introduction Vibratory finishing has been known to finish components that are either fixed on the machine setup (static fixturing) or those components that are attached to a freely floating fixture in the bulk of the polishing media in the machine (dynamic fixturing). Both these methods affect the force flow of media against the components as well as the relative velocities be- tween them [1–3]. Deployment of such fixtures therefore can reduce cycle times of the vibratory finishing process, which are typically known to be very long. Besides process optimi- zation, fixturing plays an important role in finishing high-cost components like turbine blades. On the one hand, it reduces negative effects like part-to-part collisions and damage to the finishing machine lining from sharp part edges. On the other hand, it increases the positive effect of inducing beneficial residual stresses on the finished components [4]. Mechanical fixturing, wherein components are held, is the most commonly used fixturing method. Most of the fixturing methods do not involve vibrating the component. The use of vibration-assisted finishing processes aimed to achieve quality surface finish and greater material removal in reduced times has been used in ball-burnishing [5], grinding [6], turning [7], and abrasive finishing [8] to name a few. Double vibro- polishing—incorporation of vibration to the workpiece in ad- dition to the vibrating media in the trough [9]—demonstrated 75% reduction in cycle time as compared to a mechanical fixture in a vibratory finishing machine. This was attributed to the increased normal media force impacts on the component when clamped onto the vibratory fixture. The concept of vibrating head was patented by Mermark Inc. [10] in 1989 as a novel vibratory finishing apparatus wherein only the workpiece was vibrating and the container was held stationary. However, the commercialization of the technique is less visible. Recently, the deployment of vibrato- ry fixture is a vibratory finishing trough that has demonstrated cycle time improvement [9]. Drag finishing [11, 12] is another form of fixtured mass finishing where the component is clamped by suitable means and dragged through the stationary media to impart surface finish. In this case, the component is dragged and not vibrated. Despite the prevalence of vibratory finishing, and their variations, process remains arcane and the * R. Mediratta rmediratta@ntu.edu.sg K. Ahluwalia akunal@ntu.edu.sg S. H. Yeo mshyeo@ntu.edu.sg 1 Rolls-Royce@NTU Corporate Lab, c/o School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore 2 School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore The International Journal of Advanced Manufacturing Technology https://doi.org/10.1007/s00170-018-1718-2