Lüders Deformation and Strain Aging of [001] Oriented Fe-30%Cr Alloy Single Crystals

Abstract

Peculiar deformation accompanied by Lüders band having 46% Lüders strain was observed in the [001] oriented Fe-30%Cr alloy single crystal. Specimen was again deformed after aging at 473K for 1.8ks at the 23.5% strain. The first Lüders band can not move due to locking by aging and second Lüders band started from the opposite side of the chuck. The specimen having [001] tensile axis is thought to begin to slip ideally by four slip directions. In the present case, this specimen deformed by slip of [111] and [111] directions. Thus, the slip system of Lüders band could be determined. From the surface observation of the side surface of the specimen, the propagation speed, width and the strain-rate in the Lüders band were determined. The mobile dislocation density in the Lüders band was also estimated to be about 2×10⁸cm/cm³. The effective and internal stresses were determined during the straining in order to analyze the mechanism of Lüders deformation.