Magnetomechanical damping in Fe-Cr alloys and effect of Al and Mo addition

The damping capacity of ferromagnetic Fe-Cr based alloys containing 0-8% Al and 0-4% Rile has been investigated over a wide range of frequencies and a mplitudes using a cantilever device. The resonance curves of the flat beam samples under various driving forces were recorded from which several param eters including the damping capacity (Q(-1)), Delta E effect, internal stre ss (sigma(1)) and magnetostriction constant (lambda(s)), were determined. T he variation of these parameters with chemical composition and thermal trea tment are analyzed. The results showed that the magnetostriction constant i s the key parameter to describe variation of the damping capacity in these alloys. Lower concentration of Al and Mo enhanced the damping capacity seve ral times but higher concentration above 4% decreased it drastically. Addit ion of Mo resulted in higher damping capacity than did Al. (C) 2000 Elsevie r Science S.A. All rights reserved.