Hitachi Metals Announces Development of Alloys with Improved Oxidation Resistance for Use in Fuel Cells
Hitachi Metals, Ltd. has announced its successful development of metal interconnect materials with higher oxidation resistance and strength for use in solid oxide fuel cells (SOFC).
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 (700–850°C, for example), excellent electrical conductivity, and a coefficient of thermal expansion close to that of zirconia ceramics electrolytes.
With general stainless steel (430ss, etc.), the problem of insufficient oxidation resistance has been encountered. For nickel-based alloys (Alloy 600, etc.), 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™232L, which is ferritic stainless steel. On this occasion, the company has successfully developed ZMG232J3 and ZMG232G10 which are interconnect materials that further improve electrical conductivity, oxidation resistance, and strength beyond the levels achieved in ZMG232L. 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.
"Hitachi Metals supplies high-performance materials to support the diffusion of fuel cells, which are clean," said Akitoshi Hiraki, President of Specialty Steel Company of Hitachi Metals, Ltd. "Hitachi Metals can convert energy with a high degree of efficiency, and continues to contribute to the development of an energy-saving society by providing materials and products that create energy’s future."
