The effect of thermal agitaion on atomic arrangement in alloys—II

Abstract

The transformations between a disordered arrangement of the metal atoms in an alloy at high temperatures and an ordered arrangement of the atoms at low temperatures have formed the subject of many experimental and theoretical investigations. The process of segregation into regular positions was first envisaged by Tammann in 1919. It was proved to take place in the gold-copper and other alloy systems by Johannson and Linde by X-ray investigation. Theoretical treatments of the problem have been given in papers by Borelius, Johannson, and Linde, Gorsky, and Dehlinger and Graf, and the same authors have published a large amount of experimental work on this type of transformation in the Au-Cu system. Some experiments on order-disorder transformations in the Fe-Al system, carried out by Bradley and Jay in this laboratory, led us to examine the kinetics of the change, and we recently published a paper in these Proceedings dealing with various aspects of it. Since publishing this paper, we have become aware that our theoretical treatment has in several respects a closer parallelism to those of Borelius, Gorsky, and Dehlinger than we realized at the time of writing it. We shall try to make a proper acknowledgment in the present paper.