Preface

Abstract

1.1. As is known poly-crystalline nickel-iron (containing about 50 weight percent of nickel) which has been severely cold-rolled, exhibits on recrystallization at about 1000°C a so-called cubic orientation, which means that a (100)-plane is parallel to the rolling plane and a [100]-direction is parallel to the rolling direction in every grain. Aluminium, however, which has the same cold-rolling texture does not show this cubic texture upon recrystallization. The deformation processes therefore are at all probability not the same in both cases.2.2. To trace any difference in slip mechanism between nickel-iron and aluminium the deformation and recrystallization textures of polycrystalline nickel-iron with cubic orientation were investigated. For this purpose the nickel-iron specimen was cold-rolled in a [110]-direction and parallel to a (100)-plane, and the findings were compared with observations made by Burgers and Louwerse on a single crystal of aluminium, which had likewise been cold-rolled in this same direction and parallel to this same plane.3.3. On the whole the deformation textures of cold-rolled poly-crystalline nickel-iron with cubic orientation and of a cold-rolled aluminium crystal were found to be the same. There are, however, marked differences which have a great influence on the recrystallization texture. These differences are due to the nickel-iron specimen being not a mono-crystal.4.4. The recrystallization textures of nickel-iron and aluminium which have been cold-rolled as mentioned under 2, are strongly different and only partly equal. The reason for this difference is to be found in the difference between the deformation textures. With the aid of Burgers' theory of recrystallization 9) the recrystallization texture of poly-crystalline nickel-iron could be explained fairly well. This theory, therefore, is confirmed herewith in one of its main constituents.5.5. In the second part of this article some observations made by Barrett on deformed and recrystallized aluminium are mentioned and they are compared with Burgers' theory. Barrett rejects this theory and founds this rejection on the observation that each separate newly formed grain in a poly-crystalline aluminium sample which has been deformed, exhibits on recrystallization an orientation quite different from the orientation of the deformed crystal. According to Burgers, however, such a strong deviation in orientation cannot be expected.6.6. In this paper it is shown that at least some of Barrett's observations may be explained on the basis of Burgers' theory as far as this theory contains a rule for the prediction of the recrystallization texture when the course of the deformation process and the original state of the crystal are known are known exactly.From the deformation and recrystallization textures in connection with the poly-crystalline character of the investigated nickel-iron alloy it is probable, on the other hand, that Burgers' theory needs revision in some minor respects.7.7. The difference between the deformation mechanisms in nickel-iron and aluminium as mentioned in 1 could not be cleared.