Melt processing bulk magnets-what can be achieved

High critical current density can be achieved in superconducting large YBCO grains fabricated using seeded peritectic solidification processing techniques. Such large YBCO grains are proved to be the most appropriate candidate for permanent magnet type applications. The main difficulties encountered in fabricating these materials include slow growth rate of the YBCO grains, loss of liquid in the peritectic state and control of microstructural inhomogeneity. Whereas the growth rate can be increased and liquid loss can be reduced by careful control of temperature distributions in thermal processing systems, detailed study of the mechanisms determining the microstructural inhomogeneity is required before the homogeneity of the grains can be controlled.