The study has been devoted to Ni-cermet degradation process by means of numerical simulation. Microstructure parameters of the Ni-cermet have been determined using two-dimensional images of cross-cutting sections of the samples obtained before and after long-term tests during 300, 1000, and 3000 h in the atmosphere of humidified hydrogen. Three-dimensional modeling of microstructure and determination of the volume fraction of connected nickel phase clusters have been performed. Electrical conductivity of the Ni-YSZ cermets microstructure was calculated before and after long aging tests using the finite elements method. The combination of image processing methods, three-dimensional modeling of the microstructure, and electrical conductivity simulation by means of finite element method made it possible to reveal that the relative effective electrical resistance of the Ni-cermets, measured in an atmosphere of humidified hydrogen, is directly proportional to the volume fraction of the connected nickel cluster. The dependence of the effective resistance, obtained for three-dimensional models as a result of the finite element method simulation, on the exposure time is in agreement with experimental data.

该研究通过数值模拟致力于镍金属陶瓷的降解过程。镍金属陶瓷的微观结构参数已使用在湿润氢气气氛中进行300、1000和3000小时的长期测试之前和之后获得的样品的横切面的二维图像确定。进行了微观结构的三维建模，并确定了连接的镍相簇的体积分数。使用有限元方法，在长时间老化试验前后，计算了Ni-YSZ金属陶瓷微结构的电导率。图像处理方法的组合，微观结构的三维建模，借助有限元方法进行的电导率仿真可以揭示，在湿润的氢气气氛中测得的镍金属陶瓷的相对有效电阻与所连接的镍簇的体积分数成正比。通过有限元方法仿真获得的三维模型的有效电阻对暴露时间的依赖性与实验数据一致。