Effect Of The β Phase Stabilizer Element On The Damping Property Of Ti-25.0Nb-1.5O(at.%) Alloy

Snoek-type high damping alloy is the high damping alloy based on Snoek relaxation effect caused by point defect's transition process, more specifically application of stress leads to a redistribution of the interstitial atom dissolved in the octagonal interstices in the bcc host lattice, at the same time, the vibrational energy would be dissipated.β-Ti alloy has the most application prospects of Snoek-type damping alloys.Stableβphase structure (bcc) is the most important precondition for obtaining a stable Snoek relaxation effect. The effect of eutectic type(Mo, Zr) and eutectoid type(Fe, Cr)βphase stabilizer element on theβphase stabilization, damping property, dynamical mechanical property and thermodynamic parameter of Snoek relaxation of the Ti-Nb-O alloy were studied in the paper.Moeq and Bo /Md are the important standards for estimating the stabilization of theβphase in the design process of a new Snoek-type high damping alloys. The calculated results show that Mo and Fe are the good elements forβphase stabilizer. But Mo content should be controlled between 2.0at.%and 6.5at.%, and Fe content be controlled in less than 3.0at.%.Q^-1 of the Ti-25.0Nb-1.5O(at.%) alloy is about 0.03, whenβphase stabilizer elements are added to the alloy, although the peak temperature increases and the temperature range broadens, but the damping value decrease. This phenomenon has a concern in category and content of the stabilizer elements-eutectoid type element more easily result the sharp decrease in Q-1 than the eutectic type, when the eutectic type element is not too much the alloy can has a good performance.Activation energy is one thermodynamic characteristic parameter reflecting the Snoek peak,βphase stabilizer elements can enhance the activation energy obviously. But when the activation energy sharply increase to a high level, the damping property maybe decrease sharply, if the increase of activation energy caused by decrease in the lattice constant is so high that the O atom relaxation process would be blocked.