The Effects of Static Strain on the Damping Capacity of High Damping Alloys

Influences of static strain on the damping capacity in Mn-based M2052 and Fe-6Al alloys were studied with the forced flexural oscillation method by using a dynamic mechanical analyzer (DMA). The static surface strain was applied on the 3-point bending specimens in the range of 1.0 x 10 -5 -2.0 x 10 -4 . The damping capacity of the M2052 alloy showed a continuous increase, but that of the Fe-6Al alloy showed a continuous decrease with increasing static strain in the range below 1.0 x 10 -4 , The variation of the damping capacity with increasing static strain was fitted with an exponential function, and the exponential index turned out to be 0.25 and -0.5 for the M2052 and Fe-6Al alloys, respectively. Static strains in the vicinity of 1.0 x 10 -4 caused the formation of a damping peak, which accelerated the increase of the damping capacity in the M2052 alloy, but softened the decrease of the damping capacity in the Fe-6Al alloy. A significant reduction of the damping capacity appeared at static strains above 1.0 x 10 -4 in both high damping alloys.