鉄と溶融アルミニウムの反応に及ぼす鉄の影響

抄録

Fe-Al alloy layers are formed on the surface of iron specimens, being simultaneously dissolved in liquid aluminum in the reaction between iron and liquid aluminum.
Effects of the iron in liquid aluminum on the thickness of alloy layer have hardly been investigated in connection with the weight loss of iron specimen.
In this study, behaviors of the iron in liquid aluminum were investigated by several methods. The following results were obtained.
When an iron specimen is immersed in the upper portion of an aluminum bath, the iron content is uniform in the bath. In the case of immersing the iron specimen in the lower portion, however, the iron content is higher in the lower portion than in the upper portion of the bath.
Thickness of the alloy layers rapidly increases above a certain value of the iron content in the bath. This critical value changes by the immersion time and compositions of the bath. On the other hand, the weight loss of the iron specimen decreases with increasing iron content.
The reason why the alloy layers thicken with increasing iron content in liquid aluminum is that the iron content near the iron specimen in the bath with higher iron content increases faster than in the bath with lower iron content, and that the dissolution speed of the alloy layer into the bath, therefore, decreases remarkably.