Creep of long-range-ordered Xu50Zn brass part II. Constant structure creep

In order to explain creep behaviour of beta'-brass, i.e., long-range-ordered stoichiometric Cu50Zn brass: creep experiments at constant structure based on an analysis of the strain response on sudden applied stress change were applied in the steady-state region of creep of the alloy. An original interpretation of the experimental results allows to evaluate characteristics of kinetics of dislocation slip and yields further possibilities to identify slip mechanisms. From the application of the experiments and interpretation of their results in beta'-brass, conclusions can be drawn that creep is controlled by diffusion along the high diffusivity paths, probably along superdislocations. The activation area of the slip strongly depends on the applied stress and temperature. The temperature dependence of the activation area at a given effective stress is negligible, if it exists at all. The density of mobile dislocations depends strongly on the applied stress.