Generation of compression waves by simultaneously imposing a static magnetic field and an alternating current and its use for refinement of solidified structure

A new generating method of compression waves in a liquid metal has been proposed in which a static magnetic field and an alternating current are simultaneously imposed. The theoretical expressions of intensities and distributions of pressure and velocity accompanied with the compression waves have been derived. The pressure change in liquid gallium excited by the method proposed here was measured under different intensities of the magnetic field and the alternating current. The measured pressures approximately agreed with the theoretical evaluation. The structure of a Sn-Pb alloy that was solidified under the imposition of the compression waves, was completely refined.