The mechanical damping of manganese-rich Mn–Cu sintered alloys were investigated and compared to that of M2052 cast alloy. The damping
of the sintered alloys consisting of -Mn and -MnCu phases is of the order of 10−1 and insensitive to the frequency and temperature. Single phase
-MnCu alloys, prepared by quenching from 1123 K, show two damping peaks; the large main peak is due to the twin boundaries and the small
sub-peak is due to the fct↔fcc phase transformation. These peaks are larger than those observed for the M2052 alloy. The damping of Mn–Cu
alloys aged at 723K is insensitive to temperature.