Influence of chemical composition on the damping characteristics of Cu-Al-Ni shape memory alloys

▶ Cu-XAl-4Ni SMAs with a higher content of Al exhibit lower internal friction peaks. ▶ The low inherent damping for Cu-13.5Al-4Ni is due to the 9R structure in martensite. ▶ Cu-14.0Al-4Ni exhibits high inherent damping is due to the twins in γ′1(2H) martensite.