Grain size effects on magnetomechanical damping properties of ferromagnetic Fe–5 wt.% Al alloy

To clarify the effects of grain size on the damping capacity of a ferromagnetic Fe–5 wt.% Al alloy with an average grain size of 130–845 μm, the magnetomechanical properties and microstructures were studied. The results showed a maximum damping capacity at a certain average grain size. Thus, it was proposed that the damping capacity is proportional to the total area of the 90° domain walls represented by the mean 90° domain width and the saturation magnetostriction. It can be reasonably explained that with grain growth, the saturation magnetostriction increases and the total area decreases. Leading to the result of a maximum damping capacity at a certain average grain size where the best combination of the two factors was found.