Study of structure formation and strength indicators of aluminum alloys when modified with dispersed compositions

Abstract

Promising directions of modification of aluminum alloys are studied in the field of application of powder modifiers. The use of such modifiers facilitates the technological process, is environmentally safe, leads to a uniform distribution of the introduced compositions over the cross-section of the casting, which increases the strength, plastic properties of the alloys and their stability. Purpose. The purpose of the work is to increase the mechanical properties and corrosion resistance of aluminum alloys when modified with dispersed compositions. Methodology and materials. To achieve the goal, the tasks were set: to conduct a study of a complex of mechanical properties, necessary technological characteristics, corrosion resistance and structure of alloys before and after modification. Aluminum alloys of the Al-Si, Al–Mg–Sc systems, promising for nuclear power plants, have been proposed. The materials are offered for the production of cast aluminum alloys AL9 and deformed alloys 1571. Results and discussion. The modification of aluminum alloys with a complex nano-dispersion modifier based on the plasma chemical synthesis of Mg2Si and SiC is planned. The crushed grain of modified alloys is achieved by 1.5...2 times, the mechanical strength increases by 12...18% and the corrosion resistance grows too. The results of tests on general corrosion showed that modification with a complex modifier ZrC leads to an increase in the corrosion resistance of alloys due to a decrease in the corrosion rate. The corrosion rate of AL9 alloy in the modified state was reduced from 11.04 10-6 to 9.84 10-6 kg/m2 days, which is 18%. The mechanism of complex nano-disperse modifier in aluminum melt is proposed. Conclusions. The use of such modifiers facilitates the technological process, is environmentally safe, leads to a uniform distribution of introduced nanocomposites, which increases the strength of alloys and their stability. The achieved results showed the effectiveness of modifying aluminum alloys with nano-disperse compositions.