EFFECT OF DEFORMATION TEMPERATURE ON THE BAUSCHINGER EFFECT IN POLYCRYSTALLINE ALUMINIUM.

Abstract

To study the temperature dependence of the Bauschinger effect and to obtain information about the origin of the effect, compressive flow behavior of polycrystalline aluminum prestrained by tension up to a fixed value of sigma /E ( sigma : stress, E: the Young's modulus) was investigated at temperatures between 20 and 300 degree C. Different parameters used to evaluate the Bauschinger effect in terms of stress, strain, and energy, were measured at various amounts of reversed strains. These parameters, which are considered to be closely related to dislocation structures due to pre-straining and reversed straining, showed different temperature dependences. This fact indicates that the greatest care must be taken in comparing the results of different authors. From the parameters obtained at small reversed strains it is concluded that the degree of the effect decreases with increasing temperature. Such temperature dependence of the effect is well explained from the change in dislocation structures with deformation temperature. The parameters determined at relatively large reversed strains seem to be greatly influenced by the change in dislocation structures during the reversed straining.