Effect of boron on isothermal oxidation behavior of a nickel-base superalloy with high Al and Ti contents

doi:10.1016/j.jallcom.2020.156490

CORC > 金属研究所 > 中国科学院金属研究所

	Effect of boron on isothermal oxidation behavior of a nickel-base superalloy with high Al and Ti contents
	Zhao, Guangdi 1; Zang, Ximin 1; Qi, Feng 2
刊名	JOURNAL OF ALLOYS AND COMPOUNDS
	2020-12-15
卷号	846 页码:12
关键词	Ni-based superalloy Oxidation Boron Alloying
ISSN号	0925-8388
DOI	10.1016/j.jallcom.2020.156490
通讯作者	Zhao, Guangdi(gdzhao12s@alum.imr.ac.cn)
英文摘要	The influence of boron on the oxidation resistance of conventionally cast U720Li alloy was investigated at 1130 degrees C and analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDX) and electron probe microanalysis (EPMA). It has been found that the boron-undoped and -doped alloys all obey a super-parabolic rate law, but the oxidation rate is obviously increased by the boron addition. These alloys all show non-uniform oxidation between dendritic and interdendritic areas due to the serious microsegregation, while the oxide scale morphology of the high-boron alloy is quite different from that of the boron-undoped alloy. For boron-doped alloys, in the initial stage of oxidation the outward diffusion of boron from borides formed in the interdendritic region results in the formation of discontinuous and non-uniform B-rich oxide layers beneath and inside the Cr2O3 layer, while as the oxidation proceeds further boron can also transfer from the B-rich oxide to outer layers which eventually leads to disappearance of the B-rich oxide layers. The formation of B-rich oxide layers destroys the continuity of Cr2O3 layer and decomposition of B-rich oxide layers makes Cr2O3 layer more porous, which significantly reduce the protective property of the Cr2O3 layer and in turn decrease the oxidation resistance. Moreover, the eutectic (gamma + gamma') highly enriched in Ti, Al is prone to be oxidized and form a thicker scale than the other regions, and hence the significant increase of its precipitation with boron addition also contributes to increasing the oxidation rate. (C) 2020 Elsevier B.V. All rights reserved.
资助项目	Doctor Start-up Fund of Liaoning Province[2019-BS-125] ; National Natural Science Foundation of China[51904146] ; National Natural Science Foundation of China[U1960203]
WOS研究方向	Chemistry ; Materials Science ; Metallurgy & Metallurgical Engineering
语种	英语
出版者	ELSEVIER SCIENCE SA
WOS记录号	WOS:000567764900009
资助机构	Doctor Start-up Fund of Liaoning Province ; National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/140862]
专题	金属研究所_中国科学院金属研究所
通讯作者	Zhao, Guangdi
作者单位	1.Univ Sci & Technol Liaoning, Sch Met & Mat, Anshan 114051, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Zhao, Guangdi,Zang, Ximin,Qi, Feng. Effect of boron on isothermal oxidation behavior of a nickel-base superalloy with high Al and Ti contents[J]. JOURNAL OF ALLOYS AND COMPOUNDS,2020,846:12.
APA	Zhao, Guangdi,Zang, Ximin,&Qi, Feng.(2020).Effect of boron on isothermal oxidation behavior of a nickel-base superalloy with high Al and Ti contents.JOURNAL OF ALLOYS AND COMPOUNDS,846,12.
MLA	Zhao, Guangdi,et al."Effect of boron on isothermal oxidation behavior of a nickel-base superalloy with high Al and Ti contents".JOURNAL OF ALLOYS AND COMPOUNDS 846(2020):12.