| 摘要 |
PROBLEM TO BE SOLVED: To provide Ni/YSZ cermet which generates little Ni coagulation even when exposed to high temperatures for a long time, and is capable of preventing deterioration of characteristics of a fuel electrode attributable to Ni coagulation such as crack, peeling and increase in electric resistance of the fuel electrode of a solid electrolytic type fuel cell. SOLUTION: Ni/YSZ cermet has the following characteristics, i.e., (1) the Ni/YSZ composition ratio is 24/76 to 64/36wt.%, (2) the mean grain size of particles is <=2μm, and (3) the ratio of (grain boundary of Ni and YSZ) to (total grain boundary number) >=0.4 in the number of the grain boundary in which the section of the line piercing the cermet (>=100μm in length) passes across, where total grain boundary number = grain boundary number of Ni and YSZ + grain boundary number of YSZ and YSZ + grain boundary number of Ni and Ni. That means, the cermet has the structure in which the mean grain size of particles is small, and Ni particles and YSZ particles are sufficiently dispersed. |
