摘要
以Ti-42Al-8Nb(at%)合金为研究对象,将其置于900℃空气气氛中氧化20 h,重点采用XPS手段对合金表面氧化膜结构、相组成及成分分布进行了分析。结果表明:合金经20 h氧化后,XRD结果显示氧化膜主要由Al_2O_3和Ti O_2混合物组成,而经XPS结果分析可知氧化膜最外层只有Ti O_2一种物质,次外层由Al2O3、3种不同价态的Ti氧化物及少量Ti N组成,且沿基体到外表层的方向,Ti的高价氧化物含量逐渐增多,最外表面只有Ti O_2,另外2种低价Ti氧化物含量为零,说明整个系统通过O原子的溶解、扩散完成氧化过程,导致氧化反应随时间和样品深度发生阶段性变化,从而使氧化膜沿深度方向表现出物质种类及其含量的不同。
The structure, phase composition and element distribution of the oxidation scales were analyzed by XPS for the Ti-42Al-8Nb alloys which was oxided at 900 oC for 20 h in air. It is noted that the outside of oxidation scale was composed of TiO2 only achieved by XPS, which was different from the results of the XRD analysis. The mixture of Al2O3, three titanium oxides and a few nitrides exist near the outside of the scale. The contents of Ti oxide with high valence state increased along the direction from the substrate to the outside of the sample. There was no presence of the other two Ti oxides with lower valence state in the outside of the scale, only TiO2 existed. It is concluded that the whole process of the TiAl alloy was promoted by the dissolution, diffusion of the O atom, which resulted in the multi-stage variation in the scale with different depth for different oxidation time, meanwhile resulted in the differences of the structure, composition and contents in the oxidation scales.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2016年第10期2635-2641,共7页
Rare Metal Materials and Engineering
基金
国家重点基础研究发展计划('973'计划)(2011CB605503)
