Uses of intense d.c. magnetic fields in materials processing

Apart from classical MHD effects on liquid metals such as braking of motions, stabilization of convection or shaping of free surfaces, the intense d.c. magnetic fields available from superconducting coils open the way to new phenomena which could lead to new methods in materials processing. Homogeneous magnetic field applied during solidification produce a texturation of the solid by magnetic orientation of crystallites present in the liquid. This effect is illustrated by examples of magnetic processing of high Tc superconductors, permanent magnets and biological materials. In the inhomogeneous parts of the field, a magnetic force develops related to the field gradient intensity and the material susceptibility. We present three specific applications developed recently in our research laboratory: levitation, thermomagnetic convection and phase separation.