非均相沉淀法制备Al2O3-YAG复相陶瓷

本文测量了ＹＡＧ粉体的ξ电位，通过调节ｐＨ值获得均匀分散的ＹＡＧ水悬浮液．采用非均相沉淀方法获得ＹＡＧ分布均匀的Ａｌ_２Ｏ_３－ＹＡＧ复合粉体．通过热压烧结得到致密烧结体，ＹＡＧ的加入对烧结温度的影响不大．Ａｌ_２Ｏ_３－５ｖｏｌ％ＹＡＧ复相陶瓷的抗弯强度为４８５ＭＰａ,断裂韧性为４．２ＭＰａ·ｍ^１／２，均高于单相Ａｌ_２Ｏ_３陶瓷，数据的重复性好于球磨混合所制备的样品．通过ＴＥＭ观察，ＹＡＧ颗粒均匀分布于整个样品中，表明通过非均相沉淀制粉可以获得ＹＡＧ颗粒分布均匀的Ａｌ_２Ｏ_３－ＹＡＧ复相陶瓷．

Preparation of Al2O3-YAG Composite by the Heterogeneous Precipitation Method

Zeta potential of YAG powder was measured, and well-dispersed YAG aqueous suspension could be obtained through regulating pH value. Al₂O₃-YAG composite powder containing uniformly distributed YAG was prepared by using the heterogeneous precipitation method. Sintered bodies were gotten by hot-pressing, and addition of YAG influenced little on sintering temperature. Bending strength and fracture toughness of Al₂O₃-5vol%YAG composite were 485MPa and 4.2MPa·m^1/2 respectively. Both were higher than those of monolithic Al₂O₃ ceramics, and the reliability of values was also better than that of Al₂O₃ ceramics. Through TEM observation, it could be seen that YAG particles were uniformly distributed throughout materials. It indicated that Al₂O₃-YAG composite with good YAG dispersion could be obtained by using the heterogeneous precipitation method.