A NEW PROCESS WITH A POTENTIAL TO RAPIDLY TEXTURE BULK YBA2CU3OX SUPERCONDUCTOR

A new process has been developed to texture bulk YBa2Cu3Ox superconduc tors at temperatures about 100 degrees C below the peritectic temperat ure. The texture is achieved in this process by directional recrystall ization of compacts fabricated from quenched YBCO powders. Isothermal recrystallization of quenched precursors at 890 degrees C for 3 min is found to result in the formation of more than 75% of YBa2Cu3Ox phase without any Y2BaCuO5. Recrystallization at higher temperatures leads t o rapid formation of fine Y2BaCuO5 precipitates in addition to YBa2Cu3 Ox. The formation of YBa2Cu3Ox increases with increasing heating rates . Directional recrystallization at 10 mm/h results in a well-textured microstructure with the YBa(2)Cu(3)Ox grains oriented parallel to the sample length. The magnetic field dependence of the critical current d ensity at 77K of the directionally recrystallized material compares we ll with that of melt-textured YBCO and is superior to that of magnetic ally aligned and sintered YBCO.