工艺过程对固体氧化物燃料电池材料力学性能的影响

固体氧化物燃料电池在生产过程中采用不同的加工手段,加工过程会产生一定的损伤,同时材料烧结过程产生比较大的残余应力,这些因素都会影响电池的使用寿命和完整性.本文通过实验测试,研究了不同加工过程对材料性能的影响,其中包括直接冲剪,激光切割以及切割后研磨等方法,并测试了这些加工手段对应的试件的强度.结果显示,直接冲剪法造成性能的分散性比较大,激光切割的性能较好,而研磨加工法对材料的性能影响最小；受残余应力或各层有效应力的作用,单层阳极材料的强度要高于双层电池结构材料的强度；利用弯曲法测试了半电池结构中的残余应力和不同薄膜对应的厚度残余应力,测试的结果和热弹性力学计算结果进行了对比.由于在高温时阳极材料有应力松弛现象,计算得出的残余应力高于实验测试结果.

On the Influence of Machining Process on Mechanical Properties of SOFC

In the process of solid oxide fuel cells (SOFCs) production, different machining means may produce material damage. At the same time, material sintering process produces a relatively large residual stress. Above factors will affect battery life and integrity In this paper, the influence of different machining process on mechanical properties of material was experimentally studied, including: direct punching, laser cutting and grinding after laser cutting. The strength of tested specimens was also tested. Results show that the dispersibility of mechanical property caused by direct punching is large; the property after laser cutting is good; the influence of grinding after laser cutting is minimum. By the residual stress or effective stress in different layers, material strength of monolayer anode structure is higher than that of material with bilayer structure. Based on bending test, the residual stress in half-cell structure and the residual stress corresponding to different film thickness were tested. Tested results were compared with that of thermal elasticity theory. The computed residual stress is higher than experimental results due to the stress relaxation of anode material produced by high temperature.