摘要
The experiments reveal the characteristics of stable damping in a multiphasic Al-Zn eutectoid alloy:（1）Thewhole damping(Q<sup>-1</sup>)has the same dependence on measured frequency（f）,i.e.Q<sup>-1</sup>ocf<sup>-n</sup>,where n is a parameterand is independent of temperature.（2）In a low-temperature（low-T）and low-strain-amplitude（low-A<sub>）</sub>region,Q<sup>-1</sup>=（B/）exp（-nH/kT）,where B is a parameter,H the atomic diffusion activation energy,k Boltzmann′sconstant,and T the absolute temperature.n,H<sub>o</sub>（=nH）and H are all independent of A<sub>.</sub>The damping comesfrom an anelastic motion of the phase-interface.（3）In an intermediate region including a low-Tand a high-A<sub>,</sub>a middle-T and middle A<sub> </sub>and a high-T and low-A<sub> </sub>regions,the equation Q<sup>-1</sup>=（C/f<sup>n</sup>）exp（nH/kT）stillholds,but the damping has a normal amplitude effect C,n,and H all vary with A<sub>;</sub>the damping results from anonlinear relaxation of phase-interface.（4）In a high-T and high-A<sub> </sub>region,there is no longer a linear relationship between InQ<sup>-1</sup> and T<sup>-1</sup>,whereas the relation Q<sup>-1</sup>f<sup>-n</sup> is still satisfied,where n increases as A<sub> </sub>increases,andthe damping has a normal amplitude effect but one which is weaker than that in the case（3）.The damping maybe attributed to another kind of nonlinear relaxation between phase-interfaces.
The experiments reveal the characteristics of stable damping in a multiphasic Al-Zn eutectoid alloy:(1)The whole damping(Q^(-1))has the same dependence on measured frequency(f),i.e.Q^(-1)ocf^(-n),where n is a parameter and is independent of temperature.(2)In a low-temperature(low-T)and low-strain-amplitude(low-A_)region, Q^(-1)=(B/)exp(-nH/kT),where B is a parameter,H the atomic diffusion activation energy,k Boltzmann′s constant,and T the absolute temperature.n,H_o(=nH)and H are all independent of A_.The damping comes from an anelastic motion of the phase-interface.(3)In an intermediate region including a low-Tand a high-A_, a middle-T and middle A_ and a high-T and low-A_ regions,the equation Q^(-1)=(C/f^n)exp(nH/kT)still holds,but the damping has a normal amplitude effect C,n,and H all vary with A_;the damping results from a nonlinear relaxation of phase-interface.(4)In a high-T and high-A_ region,there is no longer a linear relation ship between InQ^(-1) and T^(-1),whereas the relation Q^(-1)f^(-n) is still satisfied,where n increases as A_ increases,and the damping has a normal amplitude effect but one which is weaker than that in the case(3).The damping may be attributed to another kind of nonlinear relaxation between phase-interfaces.
出处
《中国有色金属学会会刊：英文版》
CSCD
1993年第2期58-64,共7页
Transactions of Nonferrous Metals Society of China
