Experimental investigations on chemo-mechanical magneto-rheological finishing of Al-6061 alloy using composite magnetic abrasive (CIP-Al2O3) developed via microwave-sintering route

Abstract

Magneto-rheological (MR) fluid-based surface finishing techniques rely heavily on simply mixed magnetic abrasives due to their ease of preparation. The abrasive particle's in a slurry begin to fly out from the finishing region during the surface finishing process because of the high centripetal force caused by the magnet rotational speed, reducing the process's effectiveness. To fill this void, a new CIP-Al2O3 composite magnetic abrasive is being developed via microwave sintering and proposed for the chemo-mechanical magneto-rheological finishing (CMMRF) process for their extensive performance evaluation. The composite magnetic abrasive (CIP-Al2O3) abrasive's structural and phase composition findings suggest that Al2O3 grains are tightly embedded and have strong attractive strength among the particles. The developed CIP-Al2O3 abrasives also possess the required magnetization and rheological properties for surface finishing. The experiments are carried out using a central composite design and ANOVA to correlate the output response (surface roughness and material removal rate) and parametric variables (tool speed, work-gap, and finishing time) in the CMMRF of Al-6061 alloy. A damage-free Al surface with surface qualities of Ra 59 nm is obtained after processing by CMMRF for 1 h. The rate of material removal was steadily increased to 0.379 mg/min by these magnetic abrasives. Comparing the composite magnetic abrasives' results to those with simply mixed abrasives, there is a significant improvement of 34 % in Ra value and 50 % in MRR.