LaMgAl11O19-La2Ce2O7 复合陶瓷的高温相稳定性

La2Ce2O7(LC) 和 LaMgAl11O19(LMA) 是两种新型热障涂层材料。 LC 具有优良的热物理及抗腐蚀性能， 但 其断裂韧性差。 LMA 具有良好的综合性能， 特别是力学性能优良。 基于复合材料设计理念， 为充分利用 LC 和 LMA 的优势， 本文探究了制备 LMA-LC 双相复合陶瓷的可行性。 采用高温固相法合成了 LMA 和 LC 粉末， 重 点研究了 LMA 和 LC 的高温稳定性， 初步研究了 LMA-LC 复合陶瓷块材的力学性能。 结果表明： LMA 和 LC 在 高温下发生了化学反应， 反应程度随温度升高而加剧， 主要反应产物为 LaAlO3， 其在低温下的铁弹性可能是复 合陶瓷在室温下具有良好力学性能的原因。

High Temperature Phase Stability of LaMgAl11O19-La2Ce2O7 Composite Ceramic

La2Ce2O7 (LC) and LaMgAl11O19 (LMA) are two new thermal barrier coating materials. LC shows excellent thermo-physical properties and good corrosion resistance, but its fracture toughness is poor. LMA presents good comprehensive properties, especially excellent mechanical properties. Based on the design concept of composite materials, in order to make full use of the advantages of LC and LMA, this work explores the feasibility of preparing LMA-LC double phases composite ceramics. In this paper, LMA and LC powders were synthesized by high temperature solid state method. The high temperature stability of LMA-LC was mainly studied, and the mechanical properties of LMA-LC composite ceramic bulks were preliminarily explored. The results showed that the chemical reaction between LMA and LC occurred at high temperature, and the reaction degree increased with the temperature. The main reaction product was LaAlO3. The ferroelasticity of LaAlO3 at low temperatures may be the reason for the good mechanical properties of LMA-LC bulks at room temperature.