Abstract
Vibratory finishing belongs to the wider group of near ubiquitous mass finishing processes. Components are typically bulk finished in a fluidised media bed and applications vary from performance critical polishing, to cosmetic surface preparation. The established model of surface topography development has been one of initial rapid change during a 'transient' process phase, with subsequent slowing and a final 'steady state' phase in which surface character is uniform with no dependence on process duration or initial surface finish.
Recent reassessment of the steady state phase has suggested that its surface roughness oscillates with process duration about a mean value and redefines it as the 'equilibrium' phase. Though this new model is considered to incorporate the existing model as a special case, it is argued that it represents a fundamental shift in the process mechanics. In addition, it is argued that the new findings have potential relevance to a much wider group of stochastic processes. Thus, the current paper seeks to clarify the underlying development process by investigating the nature of the end phase surface and testing these models by examining new and existing data. Results show no statistical evidence to support any periodic oscillations in the end phase surface and a number of issues with the oscillating model are noted. In addition, it is suggested that there is no clear physical mechanism to underpin the oscillating model and that the saturating model is sufficient to describe all the presented data. In conclusion a qualitative description of the end phase topography and its dynamic but temporally uniform character is given. The idea of 'process bandwidth' relating to the range of surface-media interactions is introduced to help describe some of the behavioural and control aspects of this stochastic process and the surface topography it produces.
Recent reassessment of the steady state phase has suggested that its surface roughness oscillates with process duration about a mean value and redefines it as the 'equilibrium' phase. Though this new model is considered to incorporate the existing model as a special case, it is argued that it represents a fundamental shift in the process mechanics. In addition, it is argued that the new findings have potential relevance to a much wider group of stochastic processes. Thus, the current paper seeks to clarify the underlying development process by investigating the nature of the end phase surface and testing these models by examining new and existing data. Results show no statistical evidence to support any periodic oscillations in the end phase surface and a number of issues with the oscillating model are noted. In addition, it is suggested that there is no clear physical mechanism to underpin the oscillating model and that the saturating model is sufficient to describe all the presented data. In conclusion a qualitative description of the end phase topography and its dynamic but temporally uniform character is given. The idea of 'process bandwidth' relating to the range of surface-media interactions is introduced to help describe some of the behavioural and control aspects of this stochastic process and the surface topography it produces.
Original language | English |
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Pages (from-to) | 045002 |
Number of pages | 13 |
Journal | Surface Topography: Metrology and Properties |
Volume | 6 |
Issue number | 4 |
Early online date | 18 Sep 2018 |
DOIs | |
Publication status | Published - 12 Oct 2018 |