Thermally-activated anelastic relaxation in a high-manganese Cu-Mn alloy studied by isothermal low-frequency internal friction

Low-frequency internal friction study has been conducted for a copper-manganese-rich alloy (Cu -60 at%, gamma Mn). The study used a forced torsion pendulum working in low-frequency scans at constant temperatures, damping experiments ranging between 40 Hz and 10(-4) Hz. The dependence on temperature was extended from room temperature to the spinodal curve frontier at 923 K. Phenomenological stages in anelastic relaxations of (Cu, gamma Mn) were evidenced. Three thermally activated relaxation peaks were assigned respectively to point defects (Zener relaxation), dislocation segments and dislocation walls.