Features of the structure and properties of aluminum alloys after processing by dispersed modifiers

Abstract

Studying the effect of modification with dispersed compositions on the grain structure and mechanical properties of industrial aluminum alloys is the goal of the work. Methodology. Cast aluminum alloys AL4 and AL9 were smelted in an industrial induction furnace. The alloys were modified with dispersed powder of magnesium silicide Mg2Si with a particle size of up to 200 nm. The modifier was introduced in tablet form after melting the charge with mechanical stirring of the melt. The amount of modifier to be added to the melt is calculated (0.1%). Results. The physicochemical properties of dispersed Mg2Si were studied. Experimental melting of AL4 and AL9 casting alloys was carried out. Mechanical properties of alloys were tested and analyzed in the initial state and with processing of Mg2Si melts. Dependences of the particle size and the amount of the modifier on the mechanical properties of the alloys have been established. The mechanism of interaction of the modifier with the aluminum melt during crystallization has been established. In industrial experiments, the most effective size of Mg2Si particles was established to increase σв of alloys from 110 to 260 MPa in the cast state. The optimal content of Mg2Si (0.10%) for increasing σ in aluminum alloys has been determined, and grain refinement in modified alloys and a dispersed structure have been obtained. Scientific novelty. The mechanism of action of the dispersed modifier in the melt, which includes the formation of dispersed crystallization centers, has been established. The optimal amount of modifier for melt processing has been determined and the way to enter it. Practical value. The values of the strength properties of modified alloys on the size of particles and the amount of modifier have been established. Grain refinement and uniformity of the structural components of the modified alloys have been achieved.