Composition and Structure Changes in Al₃Ni₂ Microchannel Lining Layers by Alkali Leaching

Abstract

Effects of alkali leaching time on the composition and structure changes in the Al₃Ni₂ microchannel lining layer produced by a sacrificial-core method have been investigated. The composition was measured both on the specimen surface directly exposed to the leachant and on the new surface cut after alkali leaching. In each surface, the decrease in Al concentration became sluggish after formation of Ni₃Al. On the other hand, nano structure consisted of almost pure Ni was detected on the inner wall of the microchannel leached for 864 ks.