The paper presents results of measuring attenuation coefficient of the Al-20 wt.% Zn alloy (AlZn20) inoculated with different grain

refiners. During experiments the melted alloys were doped with Al-Ti3-C0.15 refining master alloy. Basing on measurements performed

by Krautkramer USLT2000 device with 1MHz ultrasound wave frequency it was stated that grain refinement reduces the attenuation

coefficient by about 20-25%. However, the examined alloys can be still classified as the high-damping ones of attenuation greater than 150

dB/m.