Preparation and characterization of Cr2AlC microspheres prepared by spray-drying granulation

Abstract

Spray-drying granulation has been widely used to produce granules with good flowability due to its attractive features of low cost, high efficiency, and mass-production. In the present study, Cr2AlC MAX phase microspheres with particle sizes of 30–70 μm have been successfully prepared by spray-drying granulation. The main influencing factors of solid content in slurry and atomizer frequency on sphericity, size, and apparent and tap densities of spray-dried Cr2AlC microspheres were investigated under constant pumping pressure and drying temperature. By optimization of spray-drying conditions, Cr2AlC microspheres with good sphericity, flowability, and apparent and tap densities were achieved from a slurry with a solid content of 60 wt% at an atomization frequency of 280 Hz. It was found that atomization frequency and solid content in slurry influence the flowability of microspheres, while the solid content plays a major role in improving the apparent density and tap density. The microstructure and phase composition of Cr2AlC microspheres was characterized. The spray-dried Cr2AlC microspheres are promising feedstock powders for preparation of high-quality cold-sprayed Cr2AlC coatings.