研究了３种不同Ｃｏ含量双相ＣｕＣｏ合金在６００～８００℃空气中的氧化行为，合金氧化动力学遵循抛物线规律，并且在同一下抛物线速率常数随Ｃｏ含量升高和降低合鑫匀形成由Ｃｕ、Ｃｏ氧化物的复杂混合物组成的复合氧化膜，ｕ的氧化物颂向于集中在膜的外层，通常在外层膜下，是Ｃｏ的氧化物和金属Ｃｕ的混合区，对于Ｃｏ含量低于５０％（质量分数，下同）的合金，这就是Ｃｏ的内氧化区，而对含７５％Ｃｏ的合金则是在Ｃｏ氧化物的基体上分布着孤立的Cu颗粒,与固溶体二元合金不同的是,在这一区域下面的合金基体没出现Co的贫化.基于合金显微组织的双相特征,对合金氧化膜的特殊结构进行讨论.
The air oxidation of three -phase Cu-Co alloys namely Co-25 % , 50 % and 75 % GI was studied at 600 -800°C . The scaling kinetics follows only approximately the parabolic rate law, with rate constants isothemlly increasing with the Cu content. All the alloys fom ccmposite scales containing canplex mixtures of GI and Co oxides, where Cu concentrates preferentially in the external regions. Beneath the external scales there is in mt cases a region of a mixed Cooxide and Cu metal : for alloys containing up to 50 % GI this >k' ' one corresponds to the internal oxidation of Co, while for the alloy containing 25% GJ it is a Co oxide ma& "'"ctmtaining dispersion of isolated Cu particles. At variance with the behavior of solid-solution binaw alloys, Co is 'k~depleted in the alloy beneath this region in spite of its preferential local oxidation. The peculiar structure of tthe scales formed on these alloys is interpreted by considering their -phase nature.
参考文献
| [1] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%