粉体粒度及成型压力对YBa_2Cu_3O_(7-δ)超导体烧结前后致密度的影响

Influence of granularity and pressure on the density of YBa_2Cu_3O_(7-δ) superconductor before and after sintering

应用固态反应法,制备了YBaCuO超导粉体.研究了粉体粒度及成型压力对YBaCuO超导体烧结前后致密度的影响.结果表明,不同粒度YBaCuO超导粉体的压坯密度、烧结密度(即烧结前后的致密度)随压力的变化规律不同.在粉体干压成型过程中,同一粒度粉体的压坯密度随压力增大而增大;不同粒度粉体相比,粒度大的粉体压坯密度较大.在压坯烧结过程中,粒度小的粉体表面活性大,其压坯烧结密度也较大;同一粒度不同坯体的烧结密度随压坯密度的增大而增大.

The YBaCuO powders are synthesized by the solid state reaction technique. Influence of granularity and pressure on the density of YBaCuO superconductor before and after sintering are investigated. It is found that the green density and sintered density of YBa2Cu3O7-δ powders with different granularity varied differently with the variation of pressure. During the compaction of the powders, the green density is increased with the increase of pressure for the same powder; for the powders of different granularity, the larger the granularity the higher the green density. During sintering, the smaller sized powder has the higher surface energy, so its sintered ceramics has the higher sintered density; the sintered density is increased with the increase of green density for the same powder.