The internal friction /IF/ and the amplitude dependence of it /ADIF/ were studied in different Mn/7l/-Cu high damping alloys with additional small amounts of Ni or/and Si. The IF and ADIF at room temperature measured in the relative deformation range, εm /0.1 - 2/ x 10-4 decrease with increasing ageing time /0.5 - 15 hrs/ at 450°C. The decrease of the ADIF depends on the composition and the length of the previous annealing time at 850°C performed before final cold rolling. The simultaneous presence of Ni and Si did not increase significantly the specific damping capacity /at εm = 10-4/ but led to much smaller grain sizes also with short previous annealing.
展开▼
