Optimization of Tensile Strength Measurements on Glass-Ceramic Sealant Used for SOFC Stacks

Three different steel adaptors for the measurement of tensile strength values of glass-ceramic sealants were experimentally tested and analyzed by finite element analysis. It was shown that both the joining geometry and the adaptor design have an influence on the measured strength. An optimized adaptor design is proposed which offers a more uniform distribution of axial stresses within the sealing plane of the sample. Modelling results are compared with measured strength data. It was possible to obtain a tenfold increase of the measured strength values due to the optimization of adaptor setup and a mean fracture stress of 66 MPa was obtained for the material combination of KeraGlass ST K02 with Crofer® 22 APU.