Study of high temperature mechanical properties and damage behavior of Ni-YSZ anode/SrO–MgO–SiO2 glass-ceramic sealant/430 s.s. interconnect system in solid oxide fuel cells (SOFC)

Abstract

In the sealing system of Ni-YSZ anode/SrO–MgO–SiO2 glass-ceramic sealant/430 s s. interconnect, the phase transformation and mechanical properties of interfaces are studied after operating 0 h, 100 h, and 1800 h at 750 °C. The results show that the interface fracture appears in the glass/anode and glass/interconnect interfaces after operating at 1800 h. The interface mechanical parameters within different operation times are collected to investigate the effects of crystallization, penetration, and high temperature mechanical properties on the interlayer stress and structure damage. The Sr2MgSi2O7 crystal phase increases the glass modulus from 104.5 GPa to 129.8 GPa with a runtime from 0 h to 1800 h. The modulus of the Ni-YSZ interface also increases from 82.4 GPa to 128.3 GPa with the glass penetration process. The 430 s s. modulus is reduced by 13 % at 750 °C after 1800 h to reach 191.1 GPa. The established anode/glass/interconnect interlayer stress model accurately calculates the compressive stress at the glass/anode side interface and glass/interconnect side interface, with values reaching −755.2 MPa and −587.1 MPa, respectively. The crystallization zone of the SrO–MgO–SiO2 glass-side interface near Ni-YSZ and 430 s s. become the stress damage sensitive zones and break under interlayer stress.