On relationship between annealing treatment and magnetostriction behavior of Fe-16Cr-2.5Mo damping alloy

The damping capacity of Fe-16Cr-2.5Mo damping alloy was analyzed using a cantilever device. The magnetostriction property was measured using an improved Michelson interferometer. The domain morphology was optically observed using a magneto-fluid. Magnetomechanical Hysteresis Effect (MMHE) was discussed by analyzing the relationship between the magnetostriction performance and the annealing process of the alloy. The results show that the variation of saturate magnetostriction coefficient is quite consistent with that of the damping capacity of the annealed samples. With the local internal stress widely distributing in the annealed alloy, both the domain's mobility and their structure vary with the increasing annealing temperature and time. The local internal stress not only pins the domain mobility but also makes the domain structure disorder. The domain size and the number of 90° magnetic domains are responsible for the highest damping capacity of the sample annealed at 900 °C for 1 h. However, with the prolonged annealing time, the number of 90° domain decreases sharply and more heterogeneous domains appears in the alloy. The spike domains can also pin domain-walls.