Radiotracer investigation of silver grain boundary diffusion and segregation in copper bicrystals at low temperatures: the direct determination of grain boundary diffusion coefficients

低温铜双晶中银晶界扩散和偏析的放射性示踪研究：晶界扩散系数的直接测定

• 批准号: 163598987
• 负责人: Professor Dr. Sergiy Divinski
• 金额: --
• 依托单位: Institut für Materialphysik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2009
• 资助国家: 德国
• 起止时间: 2008-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/163598987?language=en
• 关键词: Radiotracer; investigation; silver; grain; boundary

The project is focused on the experimental investigation of grain boundary diffusion of Ag in Cu bicrystals. Precisely characterized near Σ5 bicrystals will be investigated. We have recently improved the sensitivity and precision of the radiotracer measurements so that, for the first time, grain boundary diffusion in a bicrystal will be determined at such low temperatures that the so-called C-type kinetic conditions will be satisfied. These measurements will provide directly the values of the solute grain boundary diffusion coefficients, Dgb, which were never measured so far in bicrystals. At higher temperatures the measurements will be performed in the so-called B-type kinetics, which yield the triple product values, , P = s • δ • Dgb, where s is the segregation factor and ± the grain boundary width. The combination the low- and high-temperature measurements performed both along and perpendicular to the tilt axis of the oriented bicrystal is the key of the project and the product s • δ and its probable anisotropy will be determined for the first time. Considerable improvement of the current understanding of grain boundary diffusion and segregation phenomena is expected from this in its completeness so far unique investigation.

本计画主要研究银在铜双晶中的晶界扩散。精确表征近1005双晶将进行研究。我们最近改进了放射性示踪剂测量的灵敏度和精度，因此，第一次，在双晶体中的晶界扩散将在如此低的温度下确定，所谓的C型动力学条件将得到满足。这些测量将直接提供溶质晶界扩散系数的值，Dgb，这是从来没有测量到目前为止在双晶。在较高温度下，测量将在所谓的B型动力学中进行，其产生三重乘积值，P = s · δ · Dgb，其中s是偏析因子，±是晶界宽度。在低温和高温下沿沿着和垂直于取向双晶倾斜轴的测量相结合是该项目的关键，并将首次确定乘积s · δ及其可能的各向异性。相当大的改善目前的理解晶界扩散和偏析现象，预计从它的完整性，到目前为止，独特的调查。