DENSIFICATION OF BI1.8(PB)0.35SR1.9CA2.1CU3OX AND TEXTURE DEVELOPMENTTHROUGH SINTER-FORGING

A technique known as sinter-forging has been used to achieve dense Bi1 .8(Pb)0.3sSr1.9Ca2.1Cu3Ox high-T(c) superconducting material with orie nted grains. The relationship between the final microstructure and pro cessing conditions was elucidated. Material density and texture increa ses with the hot-forging pressure and temperature. Grains are elongate d with the c-axis oriented approximately parallel to the direction of applied stress. The degree of grain orientation has been quantified us ing X-ray diffraction and is reported in terms of Lotgering's orientat ion factors. A maximum orientation factor of 38% was found for process ing at 830-degrees-C and 4 MPa in air. The influence of the sintering temperature and atmosphere on the electrical properties has been inves tigated. After processing at 810-degrees-C and 4 MPa, the sinter-forge d materials exhibit superconductivity, according to resistivity measur ements, with a T(c) (R=0) of 104 K. The critical current density at 77 K increases with increasing bulk density.