Hydrogen-Induced Lattice Rearrangements in Alloys

本研究探讨了金属合金中被吸附的氢原子对相变的影响。溶解的氢似乎增强了金属原子的流动性，并允许相分离，这在较低的温度下通常是看不到的。因此，氢诱导的晶格迁移率(HILM)是本计划的主题。以Pd-Rh合金体系为模型，确定了相界成分与氢含量的函数关系。氢是在高压(高达2000个大气压)下引入的。结合HELM的相分离研究扩展到钯-铂和镍-铜合金系统。在这些合金系统中选定的金属间化合物中考察了HILM诱导的金属间化合物相的有序化。电子探针分析和扫描电子显微镜等分析技术被用来表征所发生的相和相关的变化。在已有实验数据的基础上，对刀柄的作用机理进行了探讨。这项研究的结果应该阐明HILM如何有效地用于相图测定、材料合成和微合金化等领域。

This research explores the effects of absorbed hydrogen atoms on phase changes in metal alloys. Dissolved hydrogen appears to enhance metal atom mobility and allows phase separation not normally observed at lower temperatures. Hydrogen-induced lattice mobility, (HILM) is, therefore, the subject of this program. Using the palladium-rhodium alloy system as a model, phase boundary compositions are determined as a function of hydrogen content. Hydrogen is introduced under high pressures (up to 2000 atmospheres). Phase segregation studies incorporating HILM are extended to the palladium-platinum and nickel-copper alloy systems. HILM-induced ordering of intermetallic phases is examined in selected intermetallics in these alloy systems. Analytical techniques such as electron microprobe analysis and scanning transmission electron microscopy are employed to characterize the phases and related changes that occur. Mechanisms of HILM are considered based on the experimental data developed. %%% Results from this research should clarify how HILM can be used effectively in such areas as phase diagram determination, materials synthesis, and micro-alloying.