Brazing of metallic conductors onto ceramic plates in solid oxide fuel cells - Part 1 Attaching a current collector

Furnace brazing to attach metallic plates to LaCrO3 end plates in solid oxi de fuel cell (SOFC) was investigated. The metallic plates act as a current collector to which a few conducting wires made of conventional heat-resisti ng alloys can be attached. The alloy CrFe5Y(2)O(3)1 was found to be a suita ble material for the current collector because its thermal expansion coeffi cient matches that of LaCrO3 better than heat-resisting nickel- or iron-bas ed alloys. Among various filler alloys tested, SCP6 (Cu with 18 wt% Pd) ena bles the best wetting of LaCrO3 and CrFe5Y(2)O(3)1 plates, leading to good adhesion between them. Several approaches were successfully pursued to redu ce the bending of brazed LaCrO3/SCP6/CrFe5Y(2)O(3)1 joints. The area specif ic resistance of some LaCrO3/SCP6/CrFe5Y(2)O(3)1 joints increased slightly during annealing (1000 degreesC in air for 2400 h) due to oxidation in the filler alloy. Nevertheless, it remained below the target limit of 0.2 Omega . cm(2). (C) 2001 Kluwer Academic Publishers.