Effects of Self Stress on the Transport of Guest Species in Solids: Transport of Hydrogen in Metals
Effects of Self Stress on the Transport of Guest Species in Solids: Transport of Hydrogen in Metals
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DOI：
10.1021/jp013946j
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发表时间：
2002-05
影响因子：
3.3
通讯作者：
B. Legawiec;P. Żółtowski
中科院分区：
文献类型：
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作者：
B. Legawiec;P. Żółtowski
研究了氢渗透通过具有与钯或 Pd 8 1 Pt 1 9 合金相似性质的大薄膜的过程中自应力对客体在主体基质中传输的影响。系统中的平衡在膜的一侧受到氢浓度正弦信号的扰动。在另一侧，氢气浓度保持在其初始值，氢气流量就是响应。针对扰动信号的各种频率和幅度，对输运方程进行数值求解。在周期性稳态下，信号幅度越大，磁通的零次谐波和高次谐波以及基波谐波就越重要。零谐波的存在会导致氢气永久泵入整个膜。基波谐波紧密再现了通过求解线性传输方程获得的结果。这意味着，直到最大幅度，基波的频谱允许获得氢的扩散系数和金属基体的体弹性模量的可靠值。
Influence of self stress on the transport of a guest in a host matrix is studied within the process of hydrogen permeation through a large thin membrane having properties similar to those of palladium or Pd 8 1 Pt 1 9 alloy. The equilibrium in the system is perturbed at one side of the membrane by a sinusoidal signal of hydrogen concentration. At the opposite side, the hydrogen concentration is maintained at its initial value, and the flux of hydrogen is the response. The transport equations are solved numerically for a wide range of frequencies and amplitudes of the perturbing signal. At the periodic steady state, the larger the signal amplitude, the more important become the zero and higher harmonics of the flux, accompanying the fundamental harmonics. The presence of the zero harmonics causes a permanent pumping of hydrogen throughout the membrane. The fundamental harmonics closely reproduces the results obtained by solving the linearized transport equations. This means that, up to the largest amplitudes, the frequency spectrum of the fundamental harmonics allows for obtaining reliable values of the diffusion coefficient of hydrogen and the bulk elastic modulus of the metal matrix.