Characteristics of a novel atomized spherical magnetic abrasive powder

Magnetic abrasive powders (MAPs) form a flexible abrasive brush as a polishing tool and deliver a fine finish on the workpiece surface during the magnetic abrasive finishing (MAF) process. However, hard abrasives are easily thrown away from the magnetic field at high rotational speeds. The small holding force affects the finishing performance and efficiency. Therefore, a bonded type of spherical MAPs was developed via an atomization technology to overcome this disadvantage. Cubic boron nitride (CBN) abrasives were densely and uniformly embedded into the surface of MAPs. The low coercivity (Hc) and small remnant magnetization (Mr) for the prepared CBN/Fe-based MAPs suggest that the samples have excellent soft magnetic properties. The atomized MAPs were used to polish Ti-6Al-4 V in the MAF process. The effect of working gap, rotational speed of the magnetic pole, and size of MAPs on the surface roughness and material removal efficiency were investigated. Experimental results demonstrated that a fine 42-nm roughness was produced after 15 min of polishing and an optimum 17.2 mg material removal was obtained in the MAF process. Therefore, spherical CBN/Fe-based MAPs can produce a smooth surface on Ti-6Al-4 V.