The growth of metallic eutectics

Abstract

Research on this subject originated in an attempt to discover in what way the structure of certain alloys is affected by undercooling at the first moment of solidification of the eutectic. The formation around the primary crystals of an alloy of what may be called a halo or envelope of the second constituent, separating the primary crystals from the banded eutectic, has been considered by some workerd to be the result of such superfusion. It has, however, been suggested by Desch that this effect is due to segregation of the eutectic in the immediate neighbourhood of the primary during solidification. At the same time it was suggested by him that, by preventing undercooling by means of inoculation, the influence of this phenomenon on the formation of such envelopes might be investigated.