<p>Open-cell zinc alloy foams with two cell distinct sizes were fabricated by the infiltration route. Dynamic mechanical analysis (DMA) was employed to investigate the damping characteristics over mid-to-high frequencies, focusing on the variation in damping capacity as a function of temperature and frequency. The results showed that damping increases with temperature, reaching a peak value of 0.57, while exhibiting a decrease followed by an increase as the frequency rises. The damping behavior of both foams exhibited temperature and frequency dependence. Interestingly, the temperature and frequency internal friction peaks were both observed. The damping properties and internal friction mechanisms were analyzed. The temperature-dependent internal friction peaks were attributed to thermally activated phase transition mechanisms. At room temperature, the low-frequency internal friction behavior exhibited a transition from viscoelasticity to anelasticity. Unlike closed-cell metal foam, the open-cell zinc alloy foam showed the frequency-dependent internal friction peaks, which were associated with the uniform and regular open-cell structure containing a large number of internal friction sources with specific relaxation time.</p>