Influence of annealing on electrical resistance and hardness of hot-rolled aluminum alloy sheets containing up to 0.5% Zr

Resumo

We investigated the influence of multistep up to 650°C on the magnitude of resistivity and hardness of hot-rolled sheets of low-alloyed aluminum alloys containing up to 0.5 wt % Zr. Experimental samples were formed in conditions approaching those implemented for industrial installations of continuous casting and rolling. Testing procedures, including heat treatment, are described. Metallographic analysis of a cast (initial) structure and the structure of experimental samples passing the deformation was performed. Dependences of resistivity (ρ) and hardness on the temperature of the last annealing step are constructed by the results of physicomechanical tests. It is established using the computational and experimental methods that the magnitude of ρ mainly depends on the zirconium concentration in the aluminum alloy. The optimal ratio between the zirconium concentration in the alloy and annealing temperature, which makes it possible to attain the best combination of characteristics of hardness and resistivity, is determined.