11. Finishing of Curved Surface by Rotary Abrasive Float Polishing

The traditional polishing process can produce very good smooth surface but the efficiency of this process is very low for polishing of ductile, hard and brittle materials. Again, it is very difficult to generate mirror finish on irregular and curved surface workpiece. The principle issues are geometrical shape, deviations in dimension throughout the surface and no repeatability of the procedure while polishing these surfaces, therefore, it is essential to introduce a new polishing method which can overcome the aforesaid problem. Keeping in view, a rotary abrasive float polishing (RAFP) set-up has been design, fabricated and utilized for polishing of curved surface specimens. This chapter presents the properties of Alloy 61S workpiece material and fabrication of curved surface specimens by machining of Alloy 61S on CNC Vertical Milling centre ANFORD ECO VP 850. This chapter also presents the feasibility and applications of the novel polishing technique RAFP. Different concentrations abrasive slurry were prepared and used to finish the curved surface of Alloy 61S specimen. The effects of RAFP process parameters e.g. abrasive concentration, rpm, time duration on reduction in surface roughness heights ∆R_a and ∆R_t have been analyzed. The experiments were carried out based on Taguchi design of experiments and optimized the RAFP process parameters for surface roughness heights. Experimental results reveal 66.49% reduction in the surface roughness height, R_a (µm). The scanning Electron microscope (SEM) study also reveals the improvement in machined surface.