Damping Capacity of Hypo-Eutectic Zn-Al Alloys

Abstract

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.

Processing of eutectic Zn–5% Al alloy by equal-channel angular pressing

“…Kurosawa et al [43] investigated the damping capacity of hypo-eutectic Zn-Al alloys as a function of rolling ratio, and they also showed that the hardness of the cold-rolled alloy reduced with an increase in rolling reduction due to the work-softening effect. On the other hand, superplasticity due to high levels of strain rate and decreased grain size can occur in eutectic-based Zn-Al alloys during ECAP.…”

Low-Cycle Fatigue Behavior and the Combined Cyclic Hardening Material Model of Plate-Shaped Zn-22Al Alloy for Seismic Dampers

“…The primary deformation mechanism in Zn-Al alloys is grain boundary sliding, and refining the grain size of Zn-22Al alloy is effective in increasing the area of grain boundaries. This, in turn, facilitated easier sliding and enhanced superplastic deformation capability [27], as indicated by Kurosawa et al's research. Two main mechanical processing strategies are commonly employed to achieve superplasticity in Zn-Al alloy ingots: Equal Channel Angular Pressing (ECAP) and Thermomechanical Controlled Processing (TMCP), with the latter involving hot rolling.…”

Strain-induced microstructural evolution and work softening behavior of Zn–15% Al alloy

“…Zn-Al alloys are well known for their high intrinsic mechanical damping and room temperature superplasticity due to the boundaries with high mobility [7,8]. Recently, Kurosawa et al [9] have reported that the mobility of interfaces between equiaxed and ␣ grains is much greater than that concerning lamellar morphology. It implies that higher volume fraction of and ␣ grains having equiaxed morphology would lead to yielding at lower stress in response to increase in interfaces with higher mobility.…”