Al2O3颗粒形貌对注凝成型ZrO2/Al2O3陶瓷性能的影响

采用3种不同形貌的Al₂O₃原料对注凝成型制备ZrO₂/Al₂O₃（ZTA）陶瓷工艺中悬浮体的流变性能进行了研究。以低毒的单体N，N-二甲基丙烯酰胺（DMAA）制备了ZrO₂/Al₂O₃坯体和陶瓷。讨论了3种不同形貌的Al₂O₃原浆料的分散剂用量、球磨时间和固含量对浆料流变性的影响。Al₂O₃粉体呈扁平状有利于降低浆料的黏度，Al₂O₃粉体呈棒状对生坯强度的提高有利。制得的3种ZrO₂/Al₂O₃坯体颗粒间结合紧密，抗弯强度分别达到21.45，19.87，25.90 MPa。Al₂O₃粉体呈颗粒状有利于最终陶瓷力学性能的提高，陶瓷的抗弯强度及断裂韧性分别为680 MPa和7.49 MPa·m^1/2，453.1 MPa和6.8 MPa·m^1/2，549.4 MPa和6.34 MPa·m^1/2。

Effect of particle morphology of Al2O3 on gelcasting of ZrO2/Al2O3 ceramics

The rheological behaviors of the ZrO₂/Al₂O₃ (ZTA) suspension were investigated using three kinds of Al₂O₃ with different particle morphology. ZrO₂/Al₂O₃ green bodies and ceramics were prepared by using a low-toxicity monomer N,N-dimethyl acrylamide (DMAA) as gelling agent. The effect of dispersant dosage, milling time and solid loading on the rheological properties of suspension were discussed. Tabular Al₂O₃ powders have good effect on decreasing viscosity of slurries and clubbed Al₂O₃ powders are good for flexural strength of green bodies. The particles in ZrO₂/Al₂O₃ green bodies are combined closely and their bending strength can reach 21.45, 19.87, 25.90 MPa, respectively. Granular Al₂O₃ powders are beneficial properties of sintered ceramics, and the mean bending strength and fracture toughness of sintered ceramics are 680 MPa and 7.49 MPa·m^1/2, 453.1 MPa and 6.8 MPa·m^1/2, 549.4 MPa and 6.34 MPa·m^1/2.