A MnCuNiFe damping alloy with superior workability and easiness for recycle

Control of noise and vibration remains to be solved for the lowering of environmental load in all the industrial fields. It is necessary to take account of the noise and vibration problem when designing machines or structures. Therefore the development of damping materials suitable for structural parts that are easy to process and recycle, is urgently required. Mn-Cu damping alloys show the most satisfactory mechanical properties and damping capacity among the developed damping alloys. The M2052 damping alloy, which has a nominal composition of Mn-20Cu-5Ni-2Fe (at%), shows both a high damping capacity and a high strength. The damping capacity of M2052 alloy increases to a high level below a certain temperature, and the damping level also varies sensitively to the changes in vibration frequency and strain amplitude. By the peak-shift method the thermal activation energy for the (101) twin boundaries responsible for the low-temperature damping peak is calculated to be 4.88 x 10(4) J/mol. The tensile strength of the alloy is 500 MPa, accompanied with a superior workability for practical applications. It is confirmed experimentally that M2052 damping alloy is quite effective in damping the intolerable vibrations when used as structural parts.