GROWTH-MECHANISM AND MORPHOLOGY OF MELT-TEXTURE-GROWTH-PROCESSED YBA2CU3O7-X WITH DIFFERENT PRESINTERED MICROSTRUCTURES

This work deals with the influence of the starting Y-123 grain size on the growth mechanism and final microstructure of the melt-textured YB a2Cu3O7-x ceramics. Observations of the growth front morphology and st ability for the different precursors using several decomposition tempe ratures are correlated with the theoretical equations. It is found tha t the final 211 inclusion size increases as the starting 123 grain siz e increases. However, using a small-grained 123 precursor disrupts the growth front and makes the control of grain alignment difficult. An a ppropriate morphology of the 123 precursor should be chosen prior to t he MTG process in order to obtain the best properties.