부산대학교 도서관

From the viewpoint of engineering application, the Mn-Cu based alloy plates are prepared to characterize both the mechanical properties as well as the damping capacity by employing the tensile test and dynamic mechanical analysis (DMA), respectively. The microstructure of MnCu alloy were determined by optical microscopy, while the tensile fracture morphology was observed by using a scanning electron microscopy. It is verified that the mechanical properties are similar to that of A3 steel while the vibration noise across the MnCu alloy plate cut about 5-15dB off during all the experiment frequency range from 20 to 300 Hz when the alloy backing plates are applied under a turbine electric generator. The internal friction characteristic of the alloy is disclosed to be dynamic hysteresis closely related to the vibration frequency, as well as to be static hysteresis that depending on strain amplitudes. With whatever vibration frequencies or strain amplitudes, the damping capacity (tan d) of the alloy plate still shows satisfactory engineering application value higher than 0.02 at ambient temperature range around room temperature.