Hitachi Metals announced its successful development of metal interconnect materials with higher oxidation resistance and strength for use in solid oxide fuel cells.

Interconnects, an important component comprising SOFCs, function to electrically connect individual cells. Among the characteristics demanded in materials are oxidation resistance over sustained periods of time at certain operating temperature ranges excellent electrical conductivity and a coefficient of thermal expansion close to that of zirconia ceramics electrolytes.

With general stainless steel, the problem of insufficient oxidation resistance has been encountered. For nickel based alloys which have excellent oxidation resistance, the coefficient of thermal expansion is large. Likewise, alloys containing aluminum have excellent oxidation resistance but the electrical conductivity of their oxide scale is insufficient.

At Hitachi Metals, keen efforts have been advanced in the quest to develop interconnect materials capable of satisfying these required properties. Completed in 2005 was work on ZMG(TM)232L which is ferritic stainless steel. On this occasion, the Company has successfully developed ZMG(TM)232J3 and ZMG(TM)232G10 which are interconnect materials that further improve electrical conductivity, oxidation resistance, and strength beyond the levels achieved in ZMG(TM)232L.

Achievements in this area are not limited merely to the supply of materials. Steps are being taken to meet a wide range of customer needs through initiatives for processed products as well.