Mass Transport and Chemical Demixing of Y-Ba-Cu-O Compounds During Sintering in Temperature Gradients

摘要

A thin cylindrical powder compact (3mm diameter by 20mm) with a nominal composition of YBa sub 2 Cu sub 3 O/sub x/ was sintered in a static temperature gradient of 25 deg C/mm in air for 12 hours. The temperature at the hot end of the sample was maintained at 940 +- 5 deg C. Considerable mass transport and chemical demixing occurred along the length of the sample. The results are consistent with the formation of a liquid phase at the hot end of the sample, transport of the liquid down the temperature gradient and the formation different eutectic compositions along the length of the sample. The implications for processing high T/sub c/ superconductors in the system Y-Ba-Cu-O are discussed. 17 refs., 6 figs. (ERA citation 13:015182)