Local Atomic Arrangements in Alloys and Intermetallics

使用复杂的X射线散射技术研究了相干应变在相形成中的作用。相形成的初始阶段涉及局部有序区域或团簇的形成。共格应变可以影响这些团簇的组成，并改变相图。测量了镍-钒合金系统中的晶格参数，以监测基体成分和析出物成分作为主体成分和温度的函数。粘性应变有望在决定表面偏析方面发挥作用。考察了铜-金、铜-金、铜-金的晶体表面附近的局域有序性，并与块材进行了比较。%这项研究有助于更好地了解影响材料表面和本体组织和性能的因素。

The role of coherency strains in phase formation is examined using sophisticated X-ray scattering techniques. The initial stages of phase formation involve formation of locally ordered regions or clusters. Coherency strains can affect the compositions of these clusters and modify the phase diagram. Lattice parameters are measured in the nickel-vanadium alloy system to monitor matrix composition and precipitate composition as a function of bulk composition and temperature. Coherency strains are expected to have a role in determining surface segregation. Local order near crystallographic surfaces is examined in copper-gold, Cu3Au, and compared to the bulk. %%% This research provides greater understanding of the factors that influence the surface and bulk microstructure and properties of materials.