Effect of Silicon Carbide Additives on the Structure and Thermal Coefficient of Linear Expansion of a Composite Material Based on Al–Si Alloy

Abstract

The results of dilatometric and structural studies of hypereutectic aluminum silicon alloys with a content of up to 30% silicon carbide in the test temperature range of 20–120°С are presented. The influence of modifying additives of silicon carbide on the nature of changes in the structure and temperature coefficient of linear expansion (TCLE) of the resulting composite is shown. The main technological conditions for obtaining the composite material of the Al–Si–SiC system are determined by sequential melting of aluminum at 660°С, followed by the addition of Al of 30% by weight SiC to the melt, by heating to 1250°С, and 10 min exposure and pouring the melt into the coquille, which allowed to obtain a composite material with TCLR 9.22 × 10^–6 °С^–1 in the specified temperature range.