Promotion of properties of deformed aluminium alloys in modification with nanocomposites

Abstract

The objective of the work is to obtain a dispersed structure and increase the mechanical and technological properties of deformed aluminum alloys by treating melts with nanodispersed modifiers. The effect of the modification by refractory nanodispersed compositions of titanium carbonitride and silicon carbide on the grain structure and properties of aluminum alloys has been established. Aluminum alloys of the Al-Mg, Al-Mg-Sc system have been studied. The scientific novelty of the work lies in the establishment of the mechanism of influence of the nanodispersed modifier on the grain structure and the set of properties of aluminum alloys. The composition of the modifier is proposed — nanodispersed powders of silicon carbide (SiC) and titanium carbonitride (TiCN) with fractions of 50 ... 100 nm. The microstructure of alloys was studied under optical microscopes. The strength properties of the alloys were determined on a TIRAtest300 machine. Fluidity was determined using the spiral test method. In the modified samples of aluminum alloys, improved technological properties were achieved. It was found that, in alloys AMg5 and 1545, the fluidity increased by an average of 10 %. After the modification, we obtained a homogeneous dispersed structure of aluminum alloys. It turned out that the average grain size in the modified samples of alloy 1545 decreased 1.6 times in comparison with the initial state due to the increase of strength characteristics by 14… 20 %. A series of experimental-industrial melting of AMg5 and 1545 alloys has been carried out. The effective influence of a refractory modifier based on silicon carbide and titanium carbonitride on the properties of aluminum alloys has been proved. The results of the work are of practical importance for aviation and space technology products.