无容器凝固-非晶晶化法制备稀土掺杂YAG透明陶瓷的基础研究

项目名称： 无容器凝固-非晶晶化法制备稀土掺杂YAG透明陶瓷的基础研究

项目编号： No.51471158

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 李建强

作者单位： 中国科学院过程工程研究所

项目金额： 84万元

中文摘要： 稀土掺杂钇铝石榴石（YAG）透明陶瓷是重要的固体激光器用增益介质材料，具有优异的光、热、力学性能以及高温稳定性。目前YAG陶瓷的主流制备技术是粉末烧结法，要获得高透明度对原料、设备、成型和烧结工艺有极其苛刻的要求，而且存在尺寸限制等挑战。针对这个问题，本项目提出利用无容器凝固-非晶晶化法的制备YAG透明陶瓷的创新思想。首先利用无容器凝固技术解决YAG熔体玻璃形成能力弱、容易结晶的难题，使熔体在悬浮状态下深过冷进而凝固成块状玻璃基质，并研究稀土掺杂对YAG玻璃形成能力的强化机制；进而利用非晶晶化法，在较低温度（玻璃转变温度以上）晶化处理YAG玻璃即可得到高度透明的YAG陶瓷，并系统研究温度、保温时间等参数对陶瓷结构和物相的影响，阐明晶化动力学机理，优化透明陶瓷的光、热和力学性能。通过本项目研究，有望获得适合多种透明陶瓷的不同于粉末烧结法的温和工艺路线，突破现有激光增益介质材料制备技术的瓶颈。

中文关键词： 无容器凝固；非晶晶化；YAG；透明陶瓷；氧化物玻璃

英文摘要： Highly transparent Y3Al5O12 garnet (YAG) ceramic doped with rare earth metals has attracted considerable attentions since it is technologically important as laser host materials. YAG ceramic possesses the superior optical, mechanical and thermal property and stability against high temperature. However, the current sintering technique give an extremely harsh requirement on powder quality, sintering equipment, control of forming and densification process, leading to the difficulty in fabricating larger YAG transparent ceramic. In this project, we proposed a new synthetic route of YAG transparent ceramic: containerless solidification (glass) - amorphous crystallization (ceramic). Firstly, the YAG melt is levitated isolatedly by using an aerodynamic levitator with CO2 laser heating. The undercooled melt under containerless condition is apt to be frozen to bulk glass despite of its lacking of network former. The effect of rare earth doping on YAG glass forming ability will be also investigated. Secondly, highly transparent YAG polycrystalline ceramic is obtained by full crystallization from YAG bulk glass above the glass transition temperature. The effects of heat treatment parameters (temperature, dwell time, heating rate etc.) on phase, microstructure will be analyzed, and the properties of transparent ceramic are measured and optimized. By this project, we believe that this new synthetic route would be proven to be applicable and feasible to fabricate various transparent ceramic at lower temperature. The modest condition of the new route is beneficial to obtain larger laser host materials.

英文关键词： containerless solidification;glass crystallization;YAG;transparent ceramic;oxide glass