双层陶瓷膜共烧结制备过程中的应力分析

依据“受限烧结”理论，分析计算刚性支撑体上单层陶瓷膜在烧结过程中受到的应力.结果表明：单层膜在受限烧结过程中受到来自支撑体的拉应力作用，导致烧结推动力较自由烧结时降低，所需要的烧结温度比无支撑材料的烧结温度高.对于α-Al₂O₃单层膜和ZrO₂单层膜，分别计算其在受限烧结过程中受到的推动力，通过与膜层强度相关联，确定各自合适的烧结温度分别为1350和1180℃.进一步采用层状材料的共烧结应力模型计算双层膜在共烧结过程中顶层ZrO₂膜对底层α-Al₂O₃膜的压应力，当底层α-Al₂O₃膜的厚度为15μm时，顶层ZrO₂膜厚度需大于10μm，压应力的促进作用才能实现ZrO₂/α-Al₂O₃双层膜在1200℃下共烧结.

Stress Analysis in the Preparation of Bi-layer Membranes by Co-sintering Process

Based on the theory of “constrained sintering”, stress of the membrane exerted by a rigid substrate was calculated. Results show that the tensile stress from supports can decrease driving force and consequently increase the sintering temperature of supported membranes. The optimal sintering temperatures, 1350℃ and 1180℃ for α- Al₂O₃ and ZrO₂ supported membranes respectively, are determined by combining membrane strength and sintering driving force. Meanwhile, a method is proposed to calculate the stress developed in the co-sintering process of the supported multilayer membrane. For ZrO₂/α-Al₂O₃ bi-layer membrane, the calculated results show that due to the contribution of the compressive stress, the sintering driving force increases and the α-Al₂O₃ membranes can be sintered effectively after co-sintering at 1200℃. Moreover, the top-layer ZrO₂ membrane should be thicker than 10μm so as to exert sufficient compressive stress on the sub-layer α-Al₂O₃ membrane with thickness of 15μm.