Effect of annealing temperature on the magnetic properties and finishing efficiency of mechanically alloyed magnetic abrasives

In magnetic abrasive finishing (MAF) process, magnetic abrasives (MAs) act as a multipoint cutting tool that plays an important role in achieving the required surface finish of the workpiece. There are mainly two types of magnetic abrasives, bonded magnetic abrasives (BMAs) and unbounded magnetic abrasives (UMAs). BMAs are found to give better finishing capabilities than UMAs. Most of the previous research studies have applied the sintering technique for bonding abrasive particles with ferromagnetic particles. In this study, mechanical alloying technique, capable of producing a more homogeneous mixture and requiring lesser temperature for its preparation, is applied. The effect of annealing temperature on the magnetic properties and finishing efficiency is evaluated in finishing the internal surface of a brass tube. It has been found that MAs annealed at 950 °C give superior magnetic properties while MAs annealed at 1050 °C give superior finishing efficiency which improved the surface finish by 54.87% in just 10 min of finishing time. The minimum average surface roughness of the workpiece achieved is 0.51 µm in 60 min of finishing time. The working principle, cutting forces and the cutting mechanism has been represented by schematic diagrams for clear understanding.