基于三辊分散原料的3Y-ZrO2/Al2O3陶瓷的制备与表征

原料粉体的均匀分散是3Y-ZrO₂/Al₂O₃陶瓷制备的关键。在工程应用中三辊混合适合于超细陶瓷粉体高黏度浆料的分散,有利于降低分散介质用量,减少干燥时间。本工作以商用3Y-ZrO₂粉体(粒径80 nm)和粗细两种Al₂O₃粉体(粒径3μm和0.3μm)为原料,通过三辊混合、干压成型与烧结,制备3Y-ZrO₂/Al₂O₃复相陶瓷。通过XRD,SEM和万能试验机研究3Y-ZrO₂/Al₂O₃复相陶瓷的相组成、显微结构以及弯曲强度之间的关系。结果表明:在3Y-ZrO₂/Al₂O₃复相陶瓷中,除常见的Al₂O₃晶粒弥散相和ZrO₂连续相外,还存在最大尺寸5~10μm的Al₂O₃微聚集区。当添加粗Al₂O₃粉时,3Y-ZrO₂会发生从四方相到单斜相的转变。而当添加细Al₂O₃粉时,四方相的衍射峰向右偏移,同时没有检测到单斜相。对1600℃烧结的复相陶瓷样品,两种Al₂O₃粉的适量添加均有利于获得最大的弯曲强度。但对含有细Al₂O₃粉的样品,弯曲强度较粗Al₂O₃粉样品随Al₂O₃体积分数的增加更为平缓。

Fabrication and characterization of 3Y-ZrO2/Al2O3 ceramic based on the raw materials dispersed by three-roller mixing

The homogeneous dispersion of the raw materials is the key process to prepare 3 Y-ZrO₂/Al₂O₃ceramics.In engineering,the three-roller mixing is suitable for dispersing the high viscosity slurries containing the fine ceramic powders,which benefited reducing the amount of dispersion medium and drying time.The commercial 3 Y-ZrO₂powder(80 nm)and two kinds of Al₂O₃powders(3μm and 0.3μm)were used as the starting materials.3 Y-ZrO₂/Al₂O₃composite ceramics were prepared by three-roller mixing,die pressing,and sintering.The relation of phase compositions,microstructures,and bending strengths of the ceramics was investigated by XRD,SEM,and universal testing machine.The results show that the microscopic aggregation area of Al₂O₃grains with the maximum size of 5-10μm exists in the 3 Y-ZrO₂/Al₂O₃composite ceramics in addition to the normal dispersed phase of Al₂O₃and the continuous phase of 3 Y-ZrO₂.The transition from the tetragonal to the monoclinic phase of 3 Y-ZrO₂occurs with the addition of coarse Al₂O₃powders.However,the tetragonal phase shifts to the right with no monoclinic phase detected in the samples with fine Al₂O₃powders.The proper addition of the two Al₂O₃powders is beneficial to achieving the maximum bending strength when the 3 Y-ZrO₂/Al₂O₃ceramics are sintered at 1600℃.However,the curve change of the bending strength of the composite ceramics with fine Al₂O₃powder is smoother than that of the samples with coarse Al₂O₃powder with the increase of Al₂O₃volume fraction.