Stress Relaxation Tests: Modeling Issues and Applications in Magnesium Alloys and Composites

The stress relaxation (SR) test during plastic deformation is a useful technique for studying deformation processes. SR tests were performed during plastic deformation of pure magnesium, magnesium alloys and magnesium alloys-based composites over a wide temperature interval from room temperature up to 300 °C. Various theoretical approaches were applied for the estimation of characteristic parameters of thermally activated processes and finding of stress components. The aim of this study was to reveal the main features of deformation processes in hexagonal close-packed magnesium alloys and composites. The role of solute atoms in dynamic strain aging phenomena is discussed. In ultrafine-grained magnesium, grain boundary sliding during the stress relaxation tests was observed. The paper analyzes extensive set of results obtained by authors on cast and processed magnesium materials.