Microstructure-corrosion behaviour relationship of micro-alloyed Mg-0.5Zn alloy with the addition of Ca, Sr, Ag, In and Cu

• Published in: Materials & design Vol. 195; p. 108980
• Main Authors: Jin, Yiming, Blawert, Carsten, Yang, Hong, Wiese, Björn, Feyerabend, Frank, Bohlen, Jan, Mei, Di, Deng, Min, Campos, Maria Silva, Scharnagl, Nico, Strecker, Katharina, Bode, Julia, Vogt, Carla, Willumeit-Römer, Regine
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2020; Elsevier
• Subjects: Corrosion; Mg alloys; Micro-alloying; Microstructure; Micro-alloying; Corrosion; Microstructure; Mg alloys
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2020.108980

The effects of micro-addition (0.2 wt.%) of Ca, Sr, Ag, In and Cu on the microstructure and corrosion properties of the as-cast Mg-0.5Zn alloy were systematically studied. It is found that the grain refinement efficiency and intermetallics forming ability differed greatly among these elements. Si impurity also played a vital role in the precipitates formation in all systems. It is generally observed that Mg-Zn-Ca possessed the highest corrosion resistance due to the refined grain size, limited intermetallics and uniform corrosion, whereas Mg-Zn-Cu showed the highest corrosion rate due to the coarse grains, intermetallics activity and severe pitting corrosion. With the exception of Mg-Zn-Cu, the corrosion performances of Mg-0.5Zn(-0.2X) alloys were comparable with the higher concentrated systems from literature, indicating the feasibility of these micro-alloying systems for biomedical applications. [Display omitted] •The microstructures and corrosion properties of micro-alloyed Mg-0.5Zn(-0.2X) systems (X: Ca, Sr, Ag, In, Cu) are systematically studied.•Mg-Zn-Ca has the lowest corrosion rate while Mg-Zn-Cu has the highest corrosion rate in 0.9% NaCl solution.•The corrosion performances of Mg-0.5Zn(−0.2X) alloys are comparable with those of the highly-alloyed systems from literature•Si is influential in intermetallics formation and thus should be limited to avoid relevant phase formation.