A study on fine finishing of hard workpiece surfaces using fluidized elastic abrasives

Abstract

Material removal and surface generation by erosion is the principle adopted in selected manufacturing processes like abrasive jet machining and abrasive water jet cutting. As the jet velocities involved in these processes are high, they are good for material removal. With low impinging velocities, it is possible to micro erode the surface of the workpiece to achieve good finish. To achieve low velocity impingement, abrasives could be fluidized and the target surface moved against them at the required velocities. This procedure has the limitation that fine abrasive particles are difficult or impossible to fluidize and this need to be addressed to achieve significant improvement in surface finish. For this fine abrasives could be embedded on a larger carrier particle of suitable size that is easy for fluidization. If this carrier is made of elastic material, impact erosion could further be reduced paving way for improved surface finish. In this paper, such abrasive-coated elastomeric spheres of average diameter 3 mm are termed as elastic abrasives. Based on mathematical modelling and experimental investigations, the influence of major process variables and optimal operating conditions has been arrived at. At optimum operating conditions, the surface roughness (Ra value) came down to 0.0267 μm from an initial value of 0.182 μm.