Damping Capacity of Hypo-Eutectic Zn-Al Alloys

Damping capacity of hypo-eutectic Zn-Al alloys as a function of rolling ratio is investigated. Effect of heat treatment after cold rolling on the damping capacity is discussed. Damping tests were carried out using the method of the free decay of vibrations in bending oscillation. With an increase in rolling reduction, the damping capacity was increased. As the results of tensile and hardness testing show, the elongation was increased and hardness was decreased with an increase in rolling reduction. An increase in the damping capacity indicates higher value for the as rolled alloys with an accompanying work-softening effect. And the increment in the damping capacity by rolling was higher than that of the heat treated alloys. As a results of the microstructural analysis of the alloys, the grains of as rolled alloys were changed to equiaxed structures after a large rolling reduction. And the grains of the heat treated alloy was coarsened during the heat treatment. Tensile testing revealed that the maximum strain rate sensitivity, rn, was 0.35 for Zn-5%Al after 85% rolling reduction.