摘要
采用正电子多普勒展宽和X衍射分析方法研究了冷轧镍中氢化物的分解过程。实验结果指出:冷轧镍中充氢(0.5mol/lH_2 SO_4+250mg/lAS_2O_3)会产fccβ相(氢化物),β相是不稳的,室温时效将发生分解。氢化物本身对正电子不敏感,但选择适当的条件,仍可用正电子湮没技术(PAT)研究它的分解过程,所得结果与X衍射分析吻合。采用氢与空位互作用形成以氢为核心的空位团机制可较好地解释实验中观察到的现象。
The decomposition of the hydride in cold-roiled nickel is investigated by doppler broadening and X-ray method. The experimental results show that when cold-rolled nickel is charged with hydrogen in a 0.5mol/l H2SO4+ 250mg/l As2O3 solution, a fcc β phase (hydride) is formed. It is unstable and decomposes immeditely after the interuption of the charging process. Hydrogen is not sensitive for positron, but if low hydrogen concentration is introduced into the cold-rolled nickel whinin short charging time. PAT can detect the process of the hydride decomposition. Its results are consistent with the outcome using X-ray method. A mechanism of interaction between hydrogen and vacancy has been suggested, hydrogen atoms can be regarded as the centres for vacancy agglomeration, resulting in the formation of vacancy clusters. It may explain the variation of S-parameter with ageing time when the nickel hydrides decompose.
出处
《北京科技大学学报》
EI
CAS
CSCD
北大核心
1992年第3期359-363,共5页
Journal of University of Science and Technology Beijing
关键词
冷轧
镍
氢化物
分解
正电子湮没
S-para meter, cold-rolled nickel, hydride, decomposition
