High-temperature scaling of Cu-Al and Cu-Cr-Al alloys: An example of a non-classical third-element effect

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	High-temperature scaling of Cu-Al and Cu-Cr-Al alloys: An example of a non-classical third-element effect
	Y. Niu; S. Y. Wang; F. Gesmundo
	2006
发表期刊	Oxidation of Metals
ISSN	0030-770X
卷号	65 期号:5-6 页码:285-306
摘要	The oxidation of three Cu-xCr-2Al and three Cu-xCr-4Al alloys (x congruent to 0,4,8 at.%) has been investigated at 800 degrees C in 1 atm O-2. Oxidation of a binary Cu-Al alloy containing 2.2 at.% Al produced external scales composed mainly of copper oxides with small amounts of Al-rich oxide in the inner region, while the internal oxidation of Al was almost absent. The addition of 3.9 at.% Cr to this alloy was able to decrease the oxidation rate but was insufficient to prevent the oxidation of copper. Conversely, addition of 8.1 at.% Cr to the same binary alloy promoted the rather fast formation of a protective Al2O3 layer in contact with the metal substrate, with a simultaneous large decrease in the oxidation rate, producing a form of third-element effect. On the contrary, all the Cu-xCr-4Al alloys formed an internal Al2O3 layer after an initial stage during which all the alloy components were oxidized, so that the only effect of the presence of chromium was to decrease the duration of the fast initial stage. The third-element effect due to chromium additions to Cu-2Al is related to a transition from the formation of external scales composed of mixtures of Cu and Al oxides to the external growth of Al2O3-rich scales as a consequence of a thermodynamic destabilization of copper oxides associated with the formation of solid solutions between Al2O3 and Cr2O3.
部门归属	chinese acad sci, inst met res, state key lab corros & protect, shenyang 110016, peoples r china. univ genoa, dichep, i-16129 genoa, italy.;niu, y (reprint author), chinese acad sci, inst met res, state key lab corros & protect, wencui rd 62, shenyang 110016, peoples r china;yniu@imr.ac.cn
关键词	Cu-cr-al Ternary Alloys Oxidation Cr Effect High Oxidant Pressures 2-phase Binary-alloys External Oxidation Solid-solutions Atm O-2 Copper Diffusion Oxides Scales Modes
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WOS记录号	WOS:000241356600001
引用统计	被引频次：12[WOS] [WOS记录] [WOS相关记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/34412
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Y. Niu,S. Y. Wang,F. Gesmundo. High-temperature scaling of Cu-Al and Cu-Cr-Al alloys: An example of a non-classical third-element effect[J]. Oxidation of Metals,2006,65(5-6):285-306.
APA	Y. Niu,S. Y. Wang,&F. Gesmundo.(2006).High-temperature scaling of Cu-Al and Cu-Cr-Al alloys: An example of a non-classical third-element effect.Oxidation of Metals,65(5-6),285-306.
MLA	Y. Niu,et al."High-temperature scaling of Cu-Al and Cu-Cr-Al alloys: An example of a non-classical third-element effect".Oxidation of Metals 65.5-6(2006):285-306.