Journal Effect of a Liquid Phase on the Sintering of Heterogeneous YBa2Cu3O6+x Compacts

Dense, polycrystalline YBa₂Cu₃O_6+x inclusions were incorporated into YBa₂Cu₃O_6+x: powder in order to investigate the effect of nondensifying inclusions on the sintering behavior of the matrix. The presence of these inclusions caused a significant reduction in the densification rate of the matrix, as well as some microstructural damage. However, when approximately 2.5 vol% of a liquid phase was present during sintering, there was some retardation of densification in the early stages, but this disappeared with time. Also, the final sintered microstructures were damage-free and essentially identical to those of samples containing no inclusions. Possible roles for the liquid phase in correcting this microstructural damage are briefly discussed.