ISSN: 1003-6326
CN: 43-1239/TG
CODEN: TNMCEW

Vol. 29    No. 7    July 2019

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Influence of Sn addition on microstructure and corrosion resistance of AS21 magnesium alloy
Huseyin ZENGIN1, Yunus TUREN1, Hayrettin AHLATCI1, Yavuz SUN1, Abdullah Cahit KARAO?LANLI2
(1. Department of Metallurgical and Materials Engineering, Karabuk University, Turkey;
2. Department of Metallurgical and Materials Engineering, Bart?n University, Turkey
)
Abstract: This study aims to investigate the influence of Sn addition on microstructure and corrosion properties of AS21 magnesium alloys. The AS21 alloys with 0, 0.5, 1 and 2 wt.% Sn additions were produced by low pressure die casting method. Microstructure characterizations were performed by optical and scanning electron microscopy. Corrosion properties of the alloys were examined by immersion and electrochemical corrosion tests in 3.5% NaCl solution. The microscopic results showed that AS21 alloy consisted of α-Mg, isolated β-Mg17Al12 and Chinese script type Mg2Si intermetallic phases. With increasing amount of Sn, the distribution of Mg2Si phase became more discrete and denser. After 2 wt.% Sn addition, a Sn-rich network structure formed throughout the microstructure and islands of Chinese script shape were made of shorter rods of Mg2Si phase. The constant immersion corrosion tests revealed that increasing Sn addition led to a continual decrease in the degradation of AS21 alloys, in which the corrosion rate of AS21 alloy was decreased by approximately 65% with 2 wt.% Sn addition. The electrochemical corrosion tests also showed that the corrosion resistance of AS21 alloy was gradually improved with increasing Sn content.
Key words: AS21; magnesium alloy; Sn addition; microstructure; corrosion
Superintended by The China Association for Science and Technology (CAST)
Sponsored by The Nonferrous Metals Society of China (NFSOC)
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