High-damping properties of Mn-Cu sintered alloys

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 alpha-Mn and gamma-MnCu phases is of the order of 10(-1) and insensitive to the frequency and temperature. Single phase gamma-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 723 K is insensitive to temperature. (c) 2006 Elsevier B.V. All rights reserved.