Application of the Entropy Approach to Estimating the Contribution of Structural Features on the Stampability of Aluminum Alloys

Abstract

Abstract: The microstructural analysis of technical aluminum AD0 and aluminum alloys AMg2, AMg5, AMg6, and AMg10 in an annealed state is performed to estimate the size of grains and their nonuniformity, phase composition, and crystallographic texture. The method of estimating the contribution from different structural element to the structural entropy is proposed. The factors having the strongest effect on the structural entropy are revealed by using the Pareto diagrams. Crystallographic texture is established to make the greatest contribution to the total structural entropy of an alloy, whereas the grain size has the smallest effect. In turn, the chemical composition has an effect on all the structural characteristics including phase composition, grain size, and crystallographic texture. When the content of doping elements is increased, the contribution of crystallographic texture to the total structural entropy decreases, but does not prove to be less than 50% in alloy AMg10 with a maximum magnesium content. The stampability characteristics of alloys behave in different ways with an increase in the content of doping elements: the limit elongation coefficient changes slightly, as well as the structural entropy contributed by crystallographic texture. The minimum bend radius grows, as well as the mixing and phase composition entropy. Therefore, individual structural elements have a different effect on the technological properties of sheet aluminum alloys.