Interactions near the triple-phase boundaries metal/glass/air in planar solid oxide fuel cells
The possible interactions near the triple-phase boundaries (TPB) metal/glass/air, and their effects on joint strength are investigated. Two types of samples (joined couples and glass coated coupons) are prepared with the coupon of AISI 430 (nickel plated and uncoated) and a slurry of compliant silicate sealing glass (SCN-1). The joined and coated samples are heated at 850 _C for 1000 h in air. The joined couples are cooled using two different schedules and then tested in uniaxial tension. For investigating the metal-oxides precipitation procedure in glass near the TPB, glass coated coupons are either cooled at the rate of 5 _C min_1 or water-quenched from aging temperature. The mechanical test results and microstructural observations show that the spread and accelerated breakaway oxidation near TPB, which is due to continuous oxidation and dissolution of ferritic stainless steel (FSS) into the glass, leads to decreased and scattered low temperature joint strengths.