Feasibility study of hydrogenated amorphous alloys as high-damping materials

The hydrogen internal friction peak (HIFP) and the tensile strength, σf, in amorphous (denoted by ‘a’) Zr60−yCu30Al10Siy (y=0, 1) and a-Zr40Cu50−xAl10Six (x=0, 1) alloys are investigated as a function of the hydrogen concentration, CH. The drastic increase in the peak temperature, Tp, of the HIFP due to the Si addition by 1 at.% is found for the a-Zr40Cu49Al10Si1, where the decrease in 1/τ0 (τ0 denotes the pre-exponential factor of the relaxation time for the HIFP) from 1.5×1012 s−1 to 3.0×1010 s−1 is observed. On the other hand, the increase in Tp due to the Si addition by 1 at.% is much smaller for a-Zr59Cu30Al10Si1, where 1/τ0 for the HIFP in a-Zr60Cu30Al10 is already as low as that for a- Zr40Cu49Al10Si1. For the HIFP with the peak height, Qp−1, beyond 1×10−2, Qp−1 in the as-charged state decreases after heating to about 380 K because of the hydrogen induced structural relaxation (HISR). The HIFP with Qp−1 below 1×10−2 is rather stable against the HISR. It is suggested that the highly anisotropic local strain around a hydrogen atom is responsible for the very high Qp−1 and the HISR. For the high-strength and high-damping performance, σf is higher than 1.5 GPa and Qp−1 after the HISR is slightly lower than 1×10−2 for the present Zr–Cu–Al–(Si) a-alloys.