Damping capacity of the Cu−Al−Zn alloy. Report 1. Effect of chemical composition

1. The results show that the dependence of the damping capacity of the alloys of the Cu−Al−Zn system quenched in water on the electron concentration is complicated. This is caused by the effect of alloying on the level of the elastic energy stored during the direct martensitic transformation. This is indicated by the detected close correlation of the level of the damping capacity of the alloy with the temperature hysteresis of reversed martensitic transformation. 2. The damping capacity of the alloys with the electron concentration e/a<1.46–1.47 is determined by the ratio of the two types of martensite in the structure: the amount of M18R martensite increases with the increase of the zinc content and this reduces the level of the stored elastic energy and, correspondingly, the damping capacity. The increase of the aluminum content which increases the amount of 2H martensite has the opposite effect. 3. In addition to martensite, the quenched structure of the alloys with the electron concentration e/a>1.46–1.47 contains a large amount of the matrix β-phase which greatly increases the damping capacity.