Sintering and oxidation behaviors of LaCrO3-dispersed Cr alloy for metallic interconnector of solid oxide fuel cell

LaCrO3-dispersed Cr alloy for metallic interconnector in solid oxide fuel c ell has been studied as a function of LaCrO3 content in the range of 5 to 2 5 vol.%, and the sintering and oxidation properties of these alloys were ex amined. The Cr alloys were prepared from Cr and LaCrO3 powders, and were si ntered at 1500 degreesC under an Ar atmosphere with 5 vol.% H-2. The LaCrO3 -dispersed Cr alloys showed a relative density above 95%, and their sinteri ng densities did not depend on LaCrO3 content. The LaCrO3 particles in the sintered alloys existed in grain boundaries of Cr particles, and the size o f the Cr particles increased with decreasing LaCrO3 content. This means tha t LaCrO3 particles prevent grain growth of Cr particle during the sintering process. The isothermal oxidation tests of the Cr alloys were carried out for 2500 hrs at 1000 degreesC in air. The oxidation behavior obeyed a Logar ithmic Law probably due to ion diffusion within oxide scale. All Cr alloys show good oxidation resistance as compared with pure Cr, which is considere d fur LaCrO3 to increase a density of oxide scale. In particular, Cr alloys with 10 to 70 wt.% LaCrO3 are very resistant to oxidation. These results i ndicate that the LaCrO3-dispersed Cr alloys satisfy the sintered density an d oxidation resistance requirements of interconnection material in solid ox ide fuel cell.