Experimental and Theoretical Investigations of High-Temperature Creep of the ENAW 5251 (AMg2) Aluminum Alloy under Step Loading

In conditions of high-temperature creep, the evolution of the damage of metallic materials is observed. To describe this effect, the damage conception of Kachanov–Rabotnov is used. The damage parameter is defined as the relative changes in the material density, which is an integral characteristic of the damage. Taking into account this parameter and the law of conservation of mass, interrelated kinetic equations for creep deformation and the damage parameter are formulated. Analytical solutions of these equations are obtained for the case of two-stage loading. Experimental studies of the uniaxial stress state under conditions of high-temperature creep under two-stage loading of the aluminum alloy ENAW 5251 (AMg2) at a temperature of 250°C were conducted. A good agreement of the obtained theoretical curves with the experimental results is observed.