Effect of NiAl Precipitates on Strength and Damping Capacity of Fe-Cr-Al Alloys

Abstract

Strength and damping capacity of Fe-Cr-Al magneto-mechanical damping alloys doped with different amounts of Ni and Al were investigated. After slow cooling followed by homogenization, the coarse NiAl phase with the B2 structure were precipitated in the Fe-Cr-Al matrix. The precipitation of the NiAl phase was effective in increasing strength, while the damping capacity showed a low value. The coarse NiAl precipitates suppressed the motion of the magnetic domain wall necessary for magneto-mechanical damping, resulting in a decrease in internal friction. In contrast, the NiAl precipitates became fine after an appropriate heat treatment. The alloys with fine NiAl precipitates exhibited high yield stress around 1 GPa and high internal friction more than 0.04.