INFLUENCE OF NANOSIZED INCOHERENT DISPERSED PARTICLES ON THE TEMPERATURE BEHAVIOR OF FLOW STRESS IN ALUMINUM-BASED CRYSTALLINE ALLOYS

10.25712/ASTU.1811-1416.2022.01.010

Abstract

In this work, the dependence of the flow stress on the deformation temperature of dispersion-strengthened crystalline materials with an aluminum matrix and incoherent particles of the hardening phase is obtained by mathematical modeling. The studies were carried out for materials with three fixed values of the volume fraction of the hardening phase (10^-4, 0.01 and 0.1%) at two particle sizes (10 and 20 nm). It is shown that an increase in the size of incoherent particles at a fixed volume fraction of the hardening phase is accompanied by a decrease in the flow stress at all deformation temperatures. In a material with particles 10 nm in size, the dislocation structure contains prismatic dislocation loops and matrix shear-forming dislocations. As the particle size increases to 20 nm, the dislocation ensemble can additionally include dislocation dipole configurations. It has been found that an alloy with a lower content of strengthening particles can exhibit higher strength properties compared to an alloy with a higher content of strengthening incoherent particles. This is determined by the content of dislocation dipoles in the material with a lower volume fraction of the strengthening phase.