DAMPING CAPACITY IN FE-27MN-3.5SI ALLOY

Damping capacity in an Fe-27Mn-3.5Si alloy has been greatly improved with significant anisotropy by cold-rolling. The alloy, consisting of stacking faults and thermal epsilon martensite before rolling, shows poor damping capacity at low strain amplitude and strong amplitude dependence. The increase and anisotropy in the damping capacity are attributed to epsilon martensite induced by cold-rolling. The alloy is found to adjust itself to the deformation by forming epsilon martensite which has a preferred orientation of (($) over bar 101 $$($) over bar 3)epsilon [($) over bar 3032]epsilon. The mechanism of formation of the preferred orientation can be explained by the shear model in gamma-->epsilon transformation. With the result of microstructure and preferred orientation, a damping mechanism by epsilon martensite and its anisotropy is discussed.