用于YAG透明陶瓷的喷雾造粒改性粉体的制备

Preparation of modified powders by spray drying for transparent ceramics of yttrium aluminum garnet

通过喷雾造粒方法对共沉淀合成的纳米粉体进行改性,制备出球形的纳米颗粒.用XRD对粉体进行物相分析;用TEM观察了改性前粉体的颗粒形状、尺寸大小和团聚情况;用SEM观察改性前后粉体的团聚体的颗粒形状、尺寸大小与分散性,以及陶瓷热腐蚀抛光后的表面形貌.结果表明:PVB添加质量分数1.0%为最优添加量;改性后粉体所制素坯的密度显著提高,从而影响陶瓷的致密度和晶界形貌;经真空烧结制备出相对密度达99.95%的无孔净晶界YAG透明陶瓷,陶瓷晶粒的平均尺寸为10μm左右,尺寸分布较均匀,晶界清晰,晶粒中与晶界处较干净,无杂质与气孔的存在.

Nanopowders synthesized by a co-precipitation method were modified by spray drying and spherical particles were prepared for transparent ceramics of yttrium aluminum garnet.The phases of the powders were analyzed by X-ray diffraction（XRD）;the shape,size and agglomeration of the powders before modification were studied by transmission electron microscopy（TEM）;the shape,size and dispersion of the powders before and after modification were characterized and the surface morphology of polished ceramics after hot corrosion was also observed by scanning electron microscopy（SEM）.The results show that the PVB addition of 1.0% is the best;the density of molding samples by the modified powders increases significantly,thus influencing the density of the ceramic and the morphology of grain boundaries;using the vacuum sintering technology,the density of the ceramic is up to 99.95%,the average grain size is about 10 μm,the size distribution is more uniform,the grains and boundaries are clean,the impurities and porosity do not exist.