HYDROGEN IN METALS

[摘要] This thesis consists of two major research topics: (i)the thermodynamics of dilute platinum-hydrogen solid solutions and (ii)the diffusivity of hydrogen in nickel-vandium solid solutions. For the thermodynamics of dilute platinum-hydrogen solutions, the solubility of hydrogen in platinum is measured. The equilibrate-quench-analyze technique is employed. The partial molar enthalpy and excess entropy of hydrogen are calculated. It is concluded that this type of solution behaves in excellent agreement with the quasi-regular model. For the diffusivity of hydrogen in Ni-V solutions, the diffusivity is determined by using the permeation time-lag technique. It is found that (a)the hydrogen diffusivity obeys the Arrhenius relationship, and (b)the effect of V-additions is remarkably small, even for the highest V-composition (13.4 At.%). Since the addition of the vanadium caused the Ni-V matrix lattice to dilate, these observations lead us to the following conclusion: The decrease of the hydrogen mobility caused by the trapping sites adjacent to the vanadium atoms is compensated by an increase of the hydrogen mobility created by the dilation of the Ni-V matrix lattice. For a better understanding of metal-hydrogen systems, a brief review of their basic properties and applications is also included.

[发布机构] Rice University

[效力级别] Materials science