两段式无压烧结制备纳米二氧化锆(3Y)材料

研究了两段式无压烧结制备纳米二氧化锆(ZrO_2)(3Y)陶瓷材料过程中晶粒生长与致密化的协同控制。将粒度为30nm的商品纳米ZrO_2(3Y)粉体进行冷等压成型制成相对密度为49%的素坯,然后将坯体加热至1 250℃以获得94%的相对密度,后降温至1 050℃保温20 h,制得相对密度大于99%晶粒尺寸为100 nm左右的ZrO_2(3Y)。研究表明,在烧结过程中利用晶粒生长与气孔收缩的活化能的差异以协调晶粒生长与致密化的关系,找出晶界迁移与晶界扩散、晶格扩散协同作用区域,在该区域晶粒生长受到抑制,而致密化得以维持,从而实现晶粒生长的抑制和坯体的完全致密化是两段式无压烧结的关键所在。

Preparation of ZrO2(3Y) Nanoceramics Under Two-stage Non-pressurized Sintering

The compatible controlling for grain growth and densifica- tion of ZrO_2(3Y) nanoceramics under two-stage non-pressurized sinter- ing was investigated.The ZrO_2(3Y) nano-particles with the grain size of 30 nm was compacted by applying cold isostatic press of 430 MPa.The green pellets with the relative density of 49%was heated to 1250℃to obtain 94% relative density,then cooled down to 1 050℃and holding for 20 h until it was fully dense.The final grain size was 100 nm.The results showed that the sticking point of non-pressurized sintering was to find out the compatible area wherein grain growth was suppressed and densification maintain by exploiting the difference in kinetics be- tween grain-boundary diffusion and grain-boundary migration.