A STUDY OF THE EFFECTS OF ABRASIVE-FLOW FINISHING ON VARIOUS MACHINED SURFACES

Deburring and surface finishing methods represent a critical and expensive segment of the overall manufacturing process. A relatively new non-traditional process called Abrasive-Flow Machining (AFM) is being used to deburr, polish, radius, remove recast layers, or produce compressive residual stresses in a wide range of applications. Material is removed from the workpiece by the flowing of an abrasive-laden viscoelastic compound across the surface to be machined. There currently exists a lack of pertinent data which industry can use in selecting AFM for finishing workpiece surfaces generated by conventional and non-traditional machining processes. This paper presents the results of an investigation of the effects of AFM on surfaces produced by turning, milling, grinding, and wire electrical-discharge machining. The machining characteristics studied included material removal and surface finish improvement. The statistical analysis found that the type of machining process affected both metal removal and surface finish results. The initial surface condition significantly affected the amount of metal removal and was very close to meeting the significance requirement for surface finish improvement. In particular, all of the Wire EDM surfaces were improved greatly by AFM. Media viscosity significantly affected only surface improvement, while extrusion pressure did not have a significant effect in this experiment. Scanning Electron Microscopy (SEM) was used to study the surface characteristics of the workpieces. The photographs showed that AFM smoothed out the effects of the machining processes, leaving a more uniform surface. Data Dependent Systems (DDS), a stochastic modeling and analysis technique, was used to study the surface-roughness profiles before and after AFM. Overall, many similarities were found between grinding and abrasive-flow machining. This suggests that AFM is a very capable finishing process, and that its area of application should be expanded.