Particle Rotation in Colloidal Processing under a Strong Rotating Magnetic Field.

Functional ceramics with oriented crystals prepared by colloidal processing in a strong magnetic field are expected to show improved functionality. In this study, the orientation rate of particles with low magnetic susceptibility in a concentrated slurry under a strong rotating magnetic field was experimentally demonstrated using a fast photopolymerization reaction. A slurry of (Sr,Ca)2NaNb5O15 particles dispersed in an ultraviolet curable resin with a catalyst was consolidated using UV irradiation under a strong rotating magnetic field. The degree of particle orientation increased with increasing processing time and became saturated after 20 s. The orientation time was observed experimentally; the period required to achieve particle orientation was proportional to the measured viscosity of the slurry and the inverse of the square of the magnetic flux density.