Production Technology Features for Aluminum Matrix Alloys with a Silicon Carbide Framework

Abstract

Currently, good mechanical properties and a high level of thermal stability of aluminum alloy components with a composite matrix attract considerable interest for use in aerospace and automobile industries. Widespread introduction of aluminum matrix alloys with introduced solid particles of complex composition is hindered by the high production costs of preparing components and the low level of quality for the cast objects obtained. Achievement of uniform distribution of reinforcing particles within the limits of an aluminum matrix structure is one of the most important problems affecting composite material properties and quality. Questions are studied in this work of production technology for a dispersion alloy with inbuilt silicon carbide particles. A set of laboratory tests is conducted including preliminary preparation and classification of silicon carbide particles from an exhausted lining of an aluminum electrolyzer, preparation of a magnesium master alloy with introduction of particles, and preparation of objects of a composite Al–Mg–SiC alloy. Experiments are carried out with a change in SiC content from 5 to 25 wt.% and magnesium from 2 to 10 wt.%. Results of the experiments show that the technology developed is effective for preparing uniform dispersion with introduction of reinforcing particles during preliminary addition of a magnesium master alloy to molten aluminum. With an increase in amount of silicon carbide particles, a tendency is observed of an increase in strength and impact toughness of the cast billets obtained, and the beast results for ductility are achieved with a magnesium content of 7–8% and presence of 18–20% silicon carbide (SiC) particles.