Diffusion Mechanism of Atoms in Ordered Alloys at Low Temperature

低温有序合金中原子的扩散机制

基本信息

批准号：
02805081
负责人：
HASAKA Masayuki
金额：
$ 1.15万
依托单位：
Nagasaki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

The knowledge of diffusion phenomena of atoms is essential to develop new materials for modern technologies and then to use safely mechanical and electrical equipments made from those highly designed materials. The sufficient resolution of secondary iron mass spectroscopy has proved to be available for determining the small diffusion coefficients and the isotope effects of many atoms down to relatively ll"ow temperature. Our research clarified the small diffusivities and the isotope effects and the diffusion mechanisms of several solute atoms in the ordered alloys of B2, DO_3 and L1_0 types at low temperatures, by using the profit of secondary ion mass spectroscopy. The main results obtained are as follows. The temperature dependences-of diffusivities of nickel, vanadium, titanium and boron in theFe-Al alloy were not explained by a simple Arrhenius relation. The diffusivities of vanadium, titanium and boron were controlled by the change of B2 order, while the diffusivity of nickel was determined by the changes of DO_3 order as well as B2 order. The isotope effect of boron was about 0.2 in the disordered state and the ordered states of B2 and DO_3 types in the Fe-Al alloy. The diffusion of boron proceeded through highly correlated mechanism in the Fe-Al alloy. The diffusivity of boron in the ordered state of the CuAu alloy was not smaller than that extrapolated from the disordered state. The isotope effect of boron in the CuAu alloy was 0.1 in the disordered state and 0.8 in the ordered state of L1_0 type. Correlation for the diffusion of boron was stronger in the disordered state than in the ordered state.

对原子扩散现象的了解对于为现代技术开发新材料，然后使用由这些高度设计的材料制成的安全机械和电气设备至关重要。事实证明，已证明有足够的次级铁质量光谱法的足够分辨能够确定许多原子的扩散系数和同位素的效应，从而相对较小的温度。我们的研究阐明了较小的扩散性和同位素的较小的扩散效应，以及使用B2和l1_0的降低的降低原子的次数扩散机制，do_3和l1_3和l1的扩散机制，do_3和l1_3和l1的扩散机制。质量光谱的主要结果如下在无序状态下，硼的同位素效应约为0.2，而在Fe-Al合金中的B2和DO_3类型的有序状态是通过FE-AL合金中高度相关的机制进行的。硼在Cuau合金的有序状态下的扩散不小于从无序状态外推的。在无序状态下，硼在CuAU合金中的同位素效应为0.1，在L1_0类型的有序状态下为0.8。在无序状态下，硼扩散的相关性比有序状态更强。