Influence of process conditions on preparation of CBN/Fe-based spherical magnetic abrasive via gas atomization

Abstract

To meet the demand for high-performance magnetic abrasive particles (MAPs) for finishing of difficult-to-machine materials, CBN/Fe-based spherical composite MAPs were prepared via gas atomization under different process conditions. The effects of nozzle type (single-stage and two-stage), second-stage gas pressure (2, 4, 6, and 8 MPa), and the grain size of the CBN abrasive (W7 and W40) on the MAP quality were studied. The MAPs were analysed through scanning electron microscopy and energy-dispersive spectroscopy. The results indicate that the quality of MAPs prepared using two-stage atomizing nozzles is better than that of MAPs prepared using single-stage nozzles. When the second-stage gas pressure was 6 MPa, the prepared MAPs had the best sphericity, and the CBN abrasive was embedded uniformly and densely on the surface of the iron matrix. For MAPs with the same particle size, the iron matrix wrapped more effectively around CBN abrasives with smaller grain sizes. This research is can serve as a methodological reference for understanding the preparation of ceramic/metal-based spherical composite MAPs via gas atomization.