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

Abstract : Low-frequency internal friction study has been conducted for a copper-manganese-rich alloy (Cu-60 at%, γ 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, γ Mn) were evidenced. Three thermally activated relaxation peaks were assigned respectively to point defects (Zener relaxation), dislocation segments and dislocation walls.