LAUSR

Abstract Mn-Cu alloys with a high manganese content are traditional damping alloys. In this study, the effects of cyclic annealing on the spinodal decomposition of the 82.2Mn-15.8Cu-2Al(at%) alloy and the martensitic transformation and reverse martensitic transformation of the manganese-rich phase were investigated using differential scanning calorimetry (DSC) analysis, scanning electron microscopy, energy dispersive X-ray spectroscopy, internal friction analysis, and X-ray diffraction analysis. The apparent activation energy and the logarithm of the pre-exponential factor of the spinodal decomposition of the alloy and reverse martensitic transformation were calculated by the Friedman’s and Ozawa–Flynn–Wall methods. The results showed that the cyclic annealing temperature (Ta) and the cyclic annealing number (C) affect the degree of spinodal decomposition. When Ta and C increased, the heat hysteresis of the alloy became narrow. The DSC results showed that the heat hysteresis was only 0.8 K when Ta =693 K for C = 9.