Observation of Hydrogen Interactions with Defects in Metals

这项资助研究氢原子与金属缺陷相互作用的基本原理。所采用的实验技术有小角中子散射(SANS)、透射电子显微镜(TEM)、大角中子散射和伽马射线衍射。最近，SANS被证明可以直接揭示捕获在位错和钯的晶界上的氢同位素--氢的空间分布。利用SANS研究了俘获强度对氢浓度、缺陷浓度和温度的依赖关系。确定杂质偏析的相关影响，如位错和晶界上的碳和硫，是该计划不可或缺的一部分。这项研究增加了与溶质-缺陷相互作用相关的知识库，对金属和合金的机械和物理性能非常重要。

This grant investigates fundamentals of hydrogen atom interactions with defects in metals. Experimental techniques employed are small angle neutron scattering (SANS), transmission electron microscopy (TEM), large angle neutron scattering, and gamma ray diffraction. Recently it has been demonstrated that SANS can reveal directly the spatial profiles of the hydrogen isotope, deuterium, trapped at dislocations and grain boundaries in palladium. The dependency of the trapping strength on deuterium concentration, defect concentration, and temperature is examined using SANS. Determining the associated effects of impurity segregation, such as carbon and sulphur, at dislocations and grain boundaries is an integral part of this program. %%% This research adds to the knowledge base related to solute-defect interactions, important to mechanical and physical properties of metals and alloys.