The damping capacity Q(-1) of a number of Fe-16%Cr alloys containing (
0 - 6)%Al and (0 - 4)%Mo has been investigated and compared to that of
thermally sprayed coatings. The magnetomechanical hysteresis loss was
determined using a cantilever method and based on the modal analysis
technique of flat beam samples. Heat treatments usually enhanced the l
oss capability, but further annealing destroyed it drastically. The pl
asma sprayed coatings was found to require more annealing to exhibit c
omparable damping capacity to cast alloys of the same chemical composi
tion. The variation of Q(-1) versus vibration amplitude first increase
d rapidly, passed through a maximum around epsilon = 10(-4) and then d
eclined relatively slowly to its initial values. The structure of magn
etic domains were observed using the magneto-optical Kerr effect and t
heir modification following to an applied stress or magnetic field was
associated with different values of the damping capacity. The irrever
sible movement of domain walls upon application of an external stress
occurred suddenly and abruptly between two pinned positions.