M. Fukumoto et al., FABRICATION OF SOLID OXIDE FUEL-CELL ELEC TRODES BY PLASMA SPRAYING OF NI YSZ MECHANICALLY ALLOYED COMPOSITE POWDERS/, Nippon Kinzoku Gakkaishi, 58(1), 1994, pp. 50-54
In order to fabricate SOFC fuel electrodes, which were composed of a f
ine homogeneous microstructure of Ni/YSZ, plasma spraying of Ni/YSZ me
chanically alloyed composite powders was carried out. To perform this,
the oxidation heat treatments of the MA powder were introduced. Some
properties, for example, conductivity and gas permeability, of the coa
tings obtained were measured, and the applicability of MA powders to t
he fuel electrodes was evaluated. The results obtained are summarized
as follows: (1) The oxidation heat treatments to the MA powders were s
eemed to be effective in both suppression of the separation between Ni
and YSZ and maintenance of the initial composition of the powder. Fin
e-microstructure fuel electrodes were fabricated by the spraying of pr
e-oxidized MA powders. (2) The relation between conductivity of the co
ating and reduction time at 1273 K was measured. In the coating made f
rom 72 ks MA and 50%Ni contained powders, as the reduction time increa
sed the conductivity increased gradually, and the conductivity of this
coating reached the maximum value of 90 kS/m finally. (3) The gas per
meability of the coatings made from MA powders were smaller than that
of the coatings made from conventional agglomerated powders. This coul
d be improved by controlling the process parameters such as spraying c
onditions.