Effect of Sb-Rich Intermetallic Phase on the Corrosion Resistance of Zn Alloy in Near-Neutral and Acidic Solutions

doi:10.11900/0412.1961.2016.00419

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	Effect of Sb-Rich Intermetallic Phase on the Corrosion Resistance of Zn Alloy in Near-Neutral and Acidic Solutions
	Shang Xiuling 1; Zhang Bo 2; Ke Wei 2
刊名	ACTA METALLURGICA SINICA
	2017-03-11
卷号	53 期号:3 页码:351-357
关键词	Zn-1.2Sb alloy potentiodynamic polarization hydrogen evolution reaction
ISSN号	0412-1961
DOI	10.11900/0412.1961.2016.00419
通讯作者	Zhang Bo(bxz011@imr.ac.cn)
英文摘要	In the process of hot-dip galvanizing, some beneficial alloying elements are deliberately added to the molten Zn bath, in order to improve the coating properties, such as formability and corrosion resistance. Sb is one of the interesting alloying additions to the Zn bath, as it can decrease the viscosity and the surface tension of the molten Zn, contributing to producing a uniform Zn coating. Due to the low solid solubility of Sb in molten Zn at galvanising temperature, Sb-rich intermetallic particles were always found in the galvanized layers. The presence of Sb-rich phases may affect the structural properties and corrosion performance of galvanized coating. In the literature, it was reported that small addition of Sb has no significant effect on the structure and growth of galvanized layers, but a higher amount (>1%, mass fraction) of Sb can promote the dendritic solidification of Zn. In order to understand the mechanism of Sb addition on the structure and growth of galvanized coating, it is essential to identify the crystal structure of Sb-rich phases. It was reported that the Sb-rich phases found in the eta layer of a galvanized coating corresponds to the electron diffraction patterns of Sb2Zn3. However, some researchers hold that the Sb2Zn3 compound does not exist at room temperature, since it can transform to Sb3Zn4 and Zn at some elevated temperature. Consequently, in this work, the structure of Sb-rich intermetallic phase in theZn-1.2Sb (1.2%Sb) alloy has been investigated by SEM and TEM. SEM/EDS showed that Sb is present in the form of Sb-rich intermatallic phase and there is no detectable Sb in the Zn solid solution. Transmission electron diffractions analysis and EDS results indicated that the composition of Sb-rich intermatallic phases is close to that of Sb2Zn3, whereas the structure is totally different from the latter. The corrosion resistance of Zn-1.2Sb alloy has been analysed by electrochemcial polarization measurements in the different solutions. The analysed results showed that the Sb-rich phase has no obvious effect on the oxygen reduction reaction, in the aerated 0.1 mol/L NaCl (pH=6.5) solution. However, the Sb-rich phase can promote the hydrogen evolution reaction, in the deaerated acidic solution (0.1 mol/L NaCl, pH=3). Corrosion pits were found in the Zn matrix around the Sb-rich phases by SEM observations, which indicate that Zn has higher activity than Zn-Sb phase.
资助项目	National Natural Science Foundation of China[51571201]
WOS研究方向	Metallurgy & Metallurgical Engineering
语种	英语
出版者	SCIENCE PRESS
WOS记录号	WOS:000398631400008
资助机构	National Natural Science Foundation of China
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/124061]
专题	金属研究所_中国科学院金属研究所
通讯作者	Zhang Bo
作者单位	1.GD Midea Air Conditioning Equipment Co LTD, Foshan 528311, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Key Lab Nucl Mat & Safety Assessment, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Shang Xiuling,Zhang Bo,Ke Wei. Effect of Sb-Rich Intermetallic Phase on the Corrosion Resistance of Zn Alloy in Near-Neutral and Acidic Solutions[J]. ACTA METALLURGICA SINICA,2017,53(3):351-357.
APA	Shang Xiuling,Zhang Bo,&Ke Wei.(2017).Effect of Sb-Rich Intermetallic Phase on the Corrosion Resistance of Zn Alloy in Near-Neutral and Acidic Solutions.ACTA METALLURGICA SINICA,53(3),351-357.
MLA	Shang Xiuling,et al."Effect of Sb-Rich Intermetallic Phase on the Corrosion Resistance of Zn Alloy in Near-Neutral and Acidic Solutions".ACTA METALLURGICA SINICA 53.3(2017):351-357.