Densification Behavior of YBa2Cu3O7-δ Sintering
The densi fication of YBa2Cu3O7-δ to 5.9g/cm3 was achieved by the reaction sintering at 950°C for 3h with using the mixture of Y2 BaCuO5 and the unknown X phase as a starting powder under the controlled oxygen partial pressure ranging 0.1 to 0.2atm. The better sinterability was caused by the liquid phase formation during sintering. The X phase decomposed to BaCuO2 and the CuO-rich unknown phase around 600°C in oxygen partial pressure ranging 0.1 to 0.2atm. Y2BaCuO5 reacted with BaCu2 in the liquid phase formed from the CuO-rich phase above 820°C. The formation of YBa2 Cu3 O7-δ and the densi fication proceeded simultaneously, hence the high density was achieved. On the other hand the X phase oxidized to Ba3 Cu5 O8 in oxygen partial pressure ranging 0.5 to 1.0atm. Y2BaCuO5 reacted with Ba 3Cu5 O8 above 900° C with small amount of liquid phase. YBa2 Cu3 O7-δ densi fied insufficiently because the densi fication started after the formation of YBa2 Cu3 O7-δ.
KeywordsOxygen Partial Pressure Oxygen Atmosphere Reaction Sinter Densification Behavior High Oxygen Partial Pressure
Unable to display preview. Download preview PDF.
- T.Kasakoshi, Y.Ogata, Y.Iyori, K.Maruta and T.Iimura: Proc. Fall Meeting of Jpn. Soc. Powder and Powder Metallurgy 1987, 3–10.Google Scholar