On surface integrity of Hastelloy C-276 using chemo based ultrasonic assisted magnetic abrasive finishing process

Surface integrity of a machining component is crucial in applications like aerospace, automobile and marine industries as it impacts corrosion and fatigue life. In this study, the Ultrasonic Magnetic Abrasion Finishing (UAMAF) setup along with a chemical coating was used to finish the Hastelloy C-276. The responses change in the surface finish (%∆Ra) and material removal (MR) were analyzed using different process variables such as power intensity, voltage, speed, wt.% of abrasives and working gap. Further chemical coating of yttrium acetate and di-ethanolamine was applied to UAMAF specimens using physical vapor deposition. Variables such as weight of etchant, chamber temperature and the number of coatings were considered in the coating process. From the experimental results, it was observed that the surface finish improved with all process parameters except the working gap. The surface finish first increased and then decreased with working gap in the UAMAF process. MR increased with wt.% of abrasives, power intensity, and voltage while it was decreased with working gap and speed. The initial average roughness of the workpiece was Ra = 1.3 µm, and after the MAF process it reduced to Ra = 0.325 µm; further, after UAMAF it reduced to Ra = 0.096 µm, and after chemo based UAMAF, it was reduced to Ra = 0.0224 µm. However, the %∆Ra improved by around 98.3 % before and after processing and the maximum MR observed was 22.19 mg.