Development of Al2O3-SiO2 based magnetic abrasive by sintering method and its performance on Ti-6Al-4V during magnetic abrasive finishing

Abstract

ABSTRACT Magnetic abrasive finishing is a prevalent advanced method which by applying gentle forces using flexible magnetic abrasives for removing surface irregularities, provides a micro/nano range of defect-free surface finish. During magnetic abrasive finishing, magnetic forces allow the flexible magnetic abrasive particles to shear off the material from the surface in the form of microchips. During the finishing of a material having high hardness value such as titanium alloy, Nimonic alloy, and ceramics, etc., it is necessary to choose a proper magnetic abrasive considering the rate of improvement required in the surface finishing. In this research work, a new magnetic abrasive has been developed, which is suitable for finishing of Ti-6Al-4 V. The sintering method was used to develop the magnetic abrasive, and hence the developed magnetic abrasive has been named as-sintered magnetic abrasive (SMA). A mixture of abrasive powder of aluminium oxide and silicon oxide (Al2O3-SiO2) with carbonyl iron particles (ferromagnetic material) has been taken as components of sintered magnetic abrasive. The authors have studied the morphology of the sintered magnetic abrasive by scanning electron microscopy (SEM), energy dispersive spectrum (EDS), and structure by the X-ray diffraction technique. The findings reveal that the abrasives were uniformly and tightly rooted in the carbonyl iron particles. Also, magnetic abrasive finishing roughness studies on the Ti-6Al-4 V workpiece were carried to evaluate the performance of SMA. Change in the surface roughness from R a = 1.14 µm to R a = 0.85 µm was observed and atomic force microscopy (AFM) of the finished surface confirms an excellent finishing effect by the developed sintered magnetic abrasive on Ti-6Al-4 V during magnetic abrasive finishing.