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dc.contributor.advisor McLellan, Rex B.
dc.creatorYang, Liu
dc.date.accessioned 2009-06-04T00:02:53Z
dc.date.available 2009-06-04T00:02:53Z
dc.date.issued 1995
dc.identifier.urihttps://hdl.handle.net/1911/16902
dc.description.abstract The solubility of H in single crystals and polycrystalline samples of $\rm Ni\sb{3}Al$ has been measured in equilibrium with $\rm H\sb2$ gas at atmosphere. In all cases the solubility exhibits a maximum at 750 K. A structural transformation from $\rm Ll\sb2$ (cubic) to $\rm Ll\sb2$ (tetragonal) in hydrogenated $\rm Ni\sb3Al\ (Ni\sb3Al$-H) was observed. The transformation temperature was found to be between 720 K and 870 K. No enthalpy change during this transformation was detected in the DTA experiment. The diffusivity of hydrogen in $\rm Ni\sb3Al$ has been measured in the temperature range of 588 K to 1214 K using a method involving the outgassing of hydrogen charged spheres. The diffusivity of hydrogen exhibits discontinuity in the temperature range of 753 K to 793 K. Finally, the addition of Pd (0.5 wt) is shown to significantly suppress the hydrogen embrittlement of $\rm Ni\sb3Al.$ Microstructure analysis indicates no second phase is formed due to the small amount of Pd. The addition of Pd alters the fractography of $\rm Ni\sb3Al$ charged with hydrogen. It is suggested that Pd may play a role of trapping hydrogen atoms in lattice and result in reducing the hydrogen concentration around crack tips and grain boundaries, thus improving the susceptibility of $\rm Ni\sb3Al$ to hydrogen embrittlement.
dc.format.extent 108 p.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.subjectEngineering
Materials science
Mechanical engineering
dc.title The hydrogen solubility and diffusivity in nickel aluminide and developing a hydrogen tolerant nickel aluminide alloy
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Materials Science
thesis.degree.discipline Engineering
thesis.degree.grantor Rice University
thesis.degree.level Doctoral
thesis.degree.name Doctor of Philosophy
dc.identifier.citation Yang, Liu. "The hydrogen solubility and diffusivity in nickel aluminide and developing a hydrogen tolerant nickel aluminide alloy." (1995) Diss., Rice University. https://hdl.handle.net/1911/16902.


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