用RBS和RNR研究表面涂覆CeO_2对Fe-25Cr合金高温氧化的影响

A RBS AND RNA STUDY OF THE EFFECT OF CeO_2 SURFACE COATING ON HIGH-TEMPERATURE OXIDATION OF Fe-25Cr ALLOY

一、引言许多研究结果表明,将微量 Ce、Y、Hf 和 Th 或其氧化物添加于形成 Cr_2O_3保护层的 Fe～Cr 系合金中可以大大提高抗氧化性能。一些结果还表明,把这些活性元素的氧化物用涂覆方法或溅射方法作用合金表面,合金的抗氧化性能也同样可以得到改善。尽管已有许多模型试图解释这种活性元素的作用,但迄今为止,还没有一个为人们所普遍接受。

The effect of CeO_2 surface coating on the high temperature oxidation kinetics of Fe- 25Cr alloy and the Cr/Fe atom ratio in the surface layer of oxide film was investigated by Rutherford-Backscattering Spectrum (RBS) and resonant Nuclear Reaction Analgsis (RNA).The results indicated that the oxide growth rate of CeO_2 surface coated Fe-25Cr reduced about 26%,and that the Cr/Fe atom ratio in surface layer of oxide film was twice that for the alloy without CeO_2 surface coating.RBS spectra also showed that CeO_2 content in the surface layer of the oxide film reduced with oxidation time.This effect may result from the overlap of Cr_2O_3 on CeO_2.