CAJ | 학술논문

以(ZrOCl2·8H2O、Y(NO3)3·6H2O和Sc2O3为原料，聚乙二醇(PEG)为分散剂，采用化学共沉淀法制备YSZ (yttrium stabilized zirconia)(名义成分为4.5%Y2O3-ZrO2)与Sc-YSZ(名义成分为0.6%Sc2O3-YSZ)2种纳米复合陶瓷粉末(Y2O3和Sc2O3的含量均为摩尔分数)，经过压制成形后在不同温度下烧结。通过透射电镜、X射线衍射等对粉末进行表征，研究其高温下相的稳定性。结果表明：前躯体粉末在600℃煅烧2 h后都呈单一的非平衡四方相结构。采用正向滴定法制备的0.6%Sc2O3-YSZ粉末粒径约为30 nm，粉末团聚严重，有许多大的团聚体，反向滴定法制备的0.6%Sc2O3-YSZ粉末粒径约20 nm，粉末团聚少。YSZ在1200℃烧结100 h后，呈平衡四方相，并有立方相产生；1300℃烧结100 h后，平衡四方相不稳定，产生立方相和少量单斜相；在1400℃烧结100 h后，四方相全部转变为单斜相和立方相。而Sc-YSZ粉体在1200、1300和1400℃下烧结100 h后都始终保持单一的非平衡四方相结构。因此在YSZ中添加少量Sc2O3可提高其相的稳定性。
이(ZrOCl2·8H2O、Y(NO3)3·6H2O화Sc2O3위원료，취을이순(PEG)위분산제，채용화학공침정법제비YSZ (yttrium stabilized zirconia)(명의성분위4.5%Y2O3-ZrO2)여Sc-YSZ(명의성분위0.6%Sc2O3-YSZ)2충납미복합도자분말(Y2O3화Sc2O3적함량균위마이분수)，경과압제성형후재불동온도하소결。통과투사전경、X사선연사등대분말진행표정，연구기고온하상적은정성。결과표명：전구체분말재600℃단소2 h후도정단일적비평형사방상결구。채용정향적정법제비적0.6%Sc2O3-YSZ분말립경약위30 nm，분말단취엄중，유허다대적단취체，반향적정법제비적0.6%Sc2O3-YSZ분말립경약20 nm，분말단취소。YSZ재1200℃소결100 h후，정평형사방상，병유립방상산생；1300℃소결100 h후，평형사방상불은정，산생립방상화소량단사상；재1400℃소결100 h후，사방상전부전변위단사상화립방상。이Sc-YSZ분체재1200、1300화1400℃하소결100 h후도시종보지단일적비평형사방상결구。인차재YSZ중첨가소량Sc2O3가제고기상적은정성。
4.5%Y2O3-ZrO2, 0.6%Sc2O3-YSZ composite ceramic nanopowders were prepared by chemical co-precipitation method in ethanol/water (the volume ratio of alcohol to aqueous is 5:1) using ZrOCl2.8H2O, Y(NO3)3·6H2O, Sc2O3 as raw materials and polyethyleneglycol (PEG) as dispersant. The synthesized powders were characterized by means of TEM and XRD analysis. High temperature stability of composite ceramic nanopowders was also studied. The results show that, after calcined at 600 ℃ for 2 h, the presynthesized powders show the pure noneequilibrium tetragonal structure, the size of 0.6%Sc2O3-YSZ particles prepared by reverse titration method is~20 nm compared with~30 nm prepared by the straight titration method. After sintered at 1 200 ℃ for 100 h, YSZ shows equilibrium tetragonal structure together with cubic phase;after sintered at 1 300℃for 100 h, the equilibrium tetragonal structure partly transforms to cubic phase and a small amount of monoclinic phase;after sintered at 1 400℃for 100 h, the tetragonal structure transforms to cubic and monoclinic phase entirely. Whereas, 0.6%Sc2O3-YSZ keeps the pure noneequilibrium tetragonal structure after sintered at 1 200, 1 300 or 1 400℃for 100 h. Therefore, the high temperature phase stability of YSZ can be modified by addition small fraction of Sc2O3.