Preparation Of (Y_0.9Yb_0.1)₃Al₅O₁₂ Transparent Ceramics By Colloidal Processing Method

Yttrium aluminum garnet (Y3Al5O12, YAG) is an important ceramic material with promising chemical stability, optical and mechanical properties.Yb3+doped yttrium aluminum garnet (Yb:YAG) become one of the most potential laser ceramics in application because of its wide absorption and emission band, long fluorescent lifetime and good thermodynamic and mechanical property, and the most important thing is that a high doping content can be achieved in Yb:YAG ceramics. Colloidal forming has a very excellent prospect in the forming of ceramic parts. In this paper, mold pressing process, centrifugal slip casting, gel-casting and centrifugal-gel methods are used to fabricate (Y0.9Yb0.1)3Al5O12ceramics green body.In this dissertation, rare-earth doped transparent YAG ceramics powders were fabricated by using solid-state reaction method from commercial Al2O3, Y2O3, and Yb2O3powders. Comparison and analysis the (Y0.9Yb0.1)3Al5O12powder calcined in1000℃、1100℃and1200℃.The performance of the powder calcined in1000℃and1100℃is better. Comparison of the centrifugal slip casting samples with1wt%and4wt%dispersant content, indicated that increasing the dispersant content can improve the phase uniformity of the ceramic porcelain body, but the densification was difficult during sintering and the porosity increases, so the optimum dispersant content was4wt%.The sedimentation experiment and PH value experiment of aqueous Yb:YAG suspensions indicated that the optimum stabilization of PH value was about9.5.Yb:YAG transparent ceramics were prepared by mold pressing method, dipping Al3+and Y3+experiment, study found that the transmittance of sample increased with the increase of the Y3+concentration, but dipping Al3+had a contrary result.Yb:YAG transparent ceramics were prepared by gel-casting and centrifugal-gel methods. The transmittance of sample increased with the increase of the solid content. When the solid content was28vol%, the transmittance of sample prepared by gel-casting method was47.5%. However, the transmittance of sample prepared by centrifugal-gel method was only3.25%. Research the property of Yb:YAG transparent ceramics prepared by centrifugal-gel method and different gel time. When the gel time was10min, the bubbles were removed easily under the action of the centrifugal force and there was not composition segregation. At this time the transmittance of samples was relatively higher.