【摘要】 采用醇水共沉淀法制备了三元共晶成分Al₂O₃/YAG/ZrO₂粉体,在600¹350℃温度范围煅烧后研究其物相转变过程。经1300℃煅烧后Al₂O₃/YAG/ZrO₂共晶成分粉体的物相由α-Al₂O₃、c-ZrO₂和YAG构成,且具有α-Al₂O₃相包裹c-ZrO₂相的特殊结构。将煅烧粉体在1550℃下热压烧结,制备具有内晶型结构的共晶成分Al₂O₃/YAG/ZrO₂复相陶瓷,其致密度、室温抗弯强度、断裂韧性和高温（1000℃）抗弯强度分别为98.8%、420 MPa、3.69 MPa·m^1/2和464 MPa,并对复相陶瓷组织结构的形成机理进行了探讨。更多还原

【Abstract】 Al₂O₃/YAG/ZrO₂ powders with eutectic composition have been synthesized by the chemical co-precipitation in alcohol-water aqueous solution and calcination method,and were characterized by X-ray diffraction,scanning electron microscopy and transmission electron microscopy.The precursors were calcined at temperatures of 600¹350 ^oC in air,and the phase transition process was then revealed with increasing the calcination temperature.Al₂O₃/YAG/ZrO₂ powders calcined at 1300 ^oC for 1 h consist ofα-Al₂O₃,YAG and c-ZrO₂ phases.Al₂O₃/YAG/ZrO₂ ceramics with eutectic composition were hot-pressed at 1550 ^oC with the above-mentioned powders.The Al₂O₃/YAG/ZrO₂ ceramic sintered at 1550 ^oC contains an intragranular microstructure,and exhibits a relative density of 98.8%,a room-temperature flexural strength of 420 MPa,a fracture toughness of 3.69 MPa·m^1/2 and a high-temperature（1000 ^oC）flexural strength of 464 MPa.The formation mechanism of an intragranular microstructure in the Al₂O₃/YAG/ZrO₂ ceramic has been proposed.更多还原