Effect of alloyed Ca on the microstructure and corrosion properties of extruded AZ61 Mg alloy. (November 2016)

• Record Type: Journal Article
• Authors: Baek, Soo-Min; Kim, Hyeon Ju; Jeong, Hu Young; Sohn, So-Dam; Shin, Hyung-Joon; Choi, Kyung-Jin; Lee, Ki-Suk; Lee, Jung Gu; Yim, Chang Dong; You, Bong Sun; Ha, Heon-Young; Park, Sung Soo
• Is Part Of: Corrosion science. Volume 112(2016)
• Page Start: 44
• Page End: 53
• Publication Date: 2016-11
• Subjects: A. Magnesium -- A. Alloy -- B. Weight loss -- C. Pitting corrosion; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2016.07.011
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Effect of alloyed Ca on the corrosion of extruded AZ61 alloy was investigated. Alloyed Ca resulted in the formation of (Mg, Al)2 Ca and Al deficiency in the Mg matrix. Alloying with 0.1–0.5 wt% Ca resulted in increased corrosion rates in 0.6 M NaCl solution. The role of microstructural changes in corrosion properties is discussed. Abstract: Microstructure and corrosion properties of extruded AZ61 Mg alloys with varying Ca contents were investigated. Microstructure of the extruded AZ61 alloy consisted of α-Mg grains and Al8 Mn5 particles. Alloying with 0.1–0.5 wt% Ca to the AZ61 alloy resulted in the additional presence of (Mg, Al)2 Ca particles in the extruded microstructure. In 0.6 M NaCl solution at 25 °C, the extruded AZ61 alloys with 0.1–0.5 wt% Ca showed corrosion rates over 2 times faster than that of the AZ61 alloy without Ca addition. Such deteriorated corrosion resistance due to Ca addition is discussed in terms of passivation and microgalvanic corrosion.