Effect of Annealing on the Electrical Resistivity and Strengthening of Low-Alloy Alloys of the Al – Zr – Si System

Abstract

The effect of annealing at up to 550°C on the electrical resistivity ρ and HB hardness of low-alloy alloys of the Al – Zr – Si system containing up to 0.3% Zr and 0.3% Si is studied. The Thermo-Calc software is used to analyze the phase composition of the system. The computed and experimental data are used to determine the lower and upper limits for heating of cast preforms from Al – Zr alloys (shaped castings and ingots). It is shown that heating below 400°C and above 450°C is not expedient, because it increases the duration of the annealing in the former case and lowers the hardening effect due to coarsening of the Zr-containing particles in the latter case.