Achieving environment-friendly spherical polycrystalline diamond magnetic abrasives via plasma molten metal powders bonding with hard materials

High performance magnetic abrasive particles (MAPs)can contribute to the promotion of magnetic abrasive finishing (MAF) industry. In this work, environmentally friendly spherical polycrystalline diamond magnetic abrasive particles (PCD-MAPs) were prepared by plasma molten metal powders bonding with hard materials. The effects of inlet mode, outlet angle and powder concentration on the erosion wear of the spray tray were first investigated, followed by the effect of PCD powder concentration on the preparation of MAPs, and finally the microscopic morphology, phase composition, particle size distribution, magnetic properties and finishing performance of the MAPs were characterised and analyzed. The results revealed that: the erosion wear of the spray tray was smaller for the opposing inlet type with an outlet angle of 65°; the PCD-MAPs were regular spherical; the cutting edge of PCD was not carbonized and mechanically bonded to the surface layer of iron powder tightly and uniformly; the concentration of PCD powder affected the bonding number on the surface of iron powder particles; the proportion of particle size distribution between 160–212 μm and the saturation magnetic induction intensity decrease with increasing PCD concentration; the recovered PCD powder can still be used; the Ra value of TC4 titanium alloy decreases from 0.386 μm to 0.096 μm within 25 min, and the service life of PCD-MAPs exceeds 60 min. This study can provide technical support for the bonding of PCD/metal composites.