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考虑了位错平均速度V=f(σ)随时间或应变的变化之后,导出了金属在范性形变过程中内耗Q~~(-1)与位错动力学关系式V=f(σ),形变速率ε、测量频率ω、测量振幅σ_A 以及切变模量G 等的关系为(?)此处(?)t、(?)p 分别为扭切应力和拉伸应力的平均取向因子,Г(n)为取正值的积分常数,m 为除0,-1以外的整数。可见,形变过程内耗可能出现正比于(ε/ω)~(2/3)、((?)/ω)~(1/2)、((?)/ω)以及((?)/ω)~2等各种对于ω和(?)的响应行为。而且出现随测量振幅σ_A增大而减小的反常振幅效应内耗。高纯铝在拉伸速率(?)=50×10~(-6)/秒时,形变过程内耗Q~(-1)的实验数据与上式中n=-2时的结果符合得很好.此时的内耗可表示为Q~(-1)=0.245(G/σ_A)β_(-2)((?)/ω)~(1/2)/(V_0~′+β_(-2)ε~(-(1/2)).亦即Q~(-1)正比于((?)/ω)~(1/2).还观测到随着σ_A 的增加而减小的反常振幅效应内耗.高纯铝在恒速拉伸时,当ε>0.5%后,位错的平均速度(?)_0。与形变量ε间的关系可表示为(?)_0=V_0~′+βε~(-(1/2));而运动位错的密度ρ可表示为ρ=(?)/ab(V_0请下载后查看,本文暂不支持在线获取查看简介。′+βε~(-(1/2)).
Considering the variation of the average dislocation velocity V = f (σ) with time or strain, the internal friction Q ~ (-1) and dislocation kinetics of the metal during the normal deformation process are derived. V = f (σ) , The deformation rate ε, the measurement frequency ω, the measured amplitude σ_A and the shear modulus G, etc. () () t, () p are respectively the average orientation factor of torsional shear stress and tensile stress, Γ (n) is a positive integral constant, m is an integer other than 0, -1. It can be seen that the internal friction of deformation process may appear proportional to (ε / ω) ~ (2/3), ((?) / Ω) ~ (1/2) ~ 2 and so on for ω and (?) Response behavior. But also the internal friction loss due to the abnormal amplitude effect decreases with the increase of the measured amplitude σ_A. When the tensile rate (?) = 50 × 10 -6 / s, the experimental data of Q -1 in the deformation process are in good agreement with the result of n = -2 in the above formula. . The internal friction at this time can be expressed as: Q -1 -1 = 0.245 G / σ_A β _ - - 2 / (ω / 1/2) / (V_0 ~ + β_ (-2) that is, Q ~ (-1) is proportional to ((?) / ω) ~ (1/2). It is also observed that the anomalous amplitude effect that decreases as σ_A increases The internal friction of the high-purity aluminum at constant speed of drawing, when ε> 0.5%, the average velocity of dislocation () _0. The relationship between the deformation ε can be expressed as () _0 = V_0 ~ + βε ~ (- (1/2)); and the density of motion dislocation ρ can be expressed as ρ = (?) / Ab (V_0 Please download after viewing, this article is not supported for online view. /2)).