Determining kinetic energy distribution of the working medium in a centrifugal disc finishing process—part 2: experimental analysis with the use of acoustic emission signal

Abstract

This paper addresses the problem of estimating the kinetic energy distribution of the working medium in a centrifugal disc finishing process. Centrifugal disc finishing is a highly effective way of finishing surfaces, especially in the case of complex shapes, made from a variety of materials. The process is, however, frequently very time-consuming. The identification method of a region with a high kinetic energy potential by measurement of acoustic emission signal is described and verified by surface roughness tests. Signal analysis was carried out in both time and frequency domain. The results presented in experimental tests and analyses indicate that various parameters of the AE signal, including its energy, are variable and determined by abrasive particles' velocity and location in an axial cross section of the working medium. On the basis of the root mean square value of the signal, the maps of the distribution of the energy potential of the working medium are presented. Experimental results demonstrate process improvement and a significant reduction (approx 60%) of the arithmetic mean deviation of surface roughness, obtained at the same time of machining. The article also presents the functional relations between the selected AE signal descriptors and the rotational speed of the working chamber rotor. Since the article is a continuation of the previous studies, the results obtained were briefly referred to the simulation results.

Determining kinetic energy distribution of the working medium in a centrifugal disc finishing process—part 1: theoretical and numerical analysis with DEM method

“…In the companion paper [1], the experimental tests were developed to verify the results of simulation tests, to carry out experiments of the actual centrifugal disc finishing process using the AE signal and to compare the results of simulation and experimental tests.…”

“…This paper and its companion [1] describe numerical and experimental methods aimed at determining the kinetic energy distribution of the working medium in the centrifugal disc finishing process. Surface machining in centrifugal disc finishing, using a working medium in the form of abrasive particles, is an effective way of polishing the surfaces of objects with complex shapes and diverse dimensions made from a variety of materials.…”

“…Surface machining in centrifugal disc finishing, using a working medium in the form of abrasive particles, is an effective way of polishing the surfaces of objects with complex shapes and diverse dimensions made from a variety of materials. This process is not, however, fully optimized as the instantaneous value of the working energy of specific particles affecting these objects' surfaces is variable [2,3]. The value of this energy is dependent on the temporary location and orientation of objects in the working medium [4,5] and it depends directly on the local velocity of the working medium.…”

Research on the influence of workpiece orientation during processing in disc centrifugal machine on the geometrical structure of its surface and processing efficiency

“…Moreover, as the research carried out at the Department of Production Engineering has shown, there is a differentiation of the energy distribution of the working charge in its shaped spatial structure at a given rotational speed [1,2] (Fig. 2).…”

“…The paths of movement of the abrasive media in the working container of the disc centrifugal machine [1, The paths of movement of the abrasive media in the working container of the disc centrifugal machine[1,2] …”