The effect of heating chill cast eutectics

This investigation is the result of the author\u27s specific interest in two phase systems. In the past, considerable work has been done investigating the alteration of eutectoid structures; however, eutectic structures have been neglected to a great extent. Tammann did some work on the subject in 1937 as did Brown and Guy in more recent times. In both of the above cases the eutectic structure was altered by cold working and subsequent heating of the alloy. Tammann also noted that eutectics chill cast in liquid air display a vastly different structure than those cast under equilibrium conditions and that there was some shrinkage of the unworked needles after heat treatment. Eutectic and eutectoid structures show many similarities. Using normal microscopic techniques, one finds it difficult to note a difference between them except that the eutectoid is usually a finer structure. In the light of the above, it would seem reasonable that could a fine enough eutectic structure be produced, then it could, perhaps, be expected to respond to spheroidizing heat treatments in a manner similar to eutectoids. This investigation was started in an effort to determine what effect chill casting and subsequent heat treatment has upon eutectic structures --Introduction, pages 1-2