Effect of Sc/Sm microalloying on microstructural and properties of Mg-2Zn-0.3Ca biodegradable alloy
By Yang, Liuzhong; Feng, Yan; He, Yuqing; Yang, Linyi; Liu, Hanchuan; Wang, Xinfa; Peng, Chaoqun; Wang, Richu
Published in Journal of Alloys and Compounds
2022
Abstract
The influences of Sc/Sm microalloying on microstructure, mechanical property, bio-corrosion behavior and biocompatibility of the as-cast Mg-2Zn-0.3Ca alloy have been investigated in the study. The results demonstrate that Sc microalloying obviously refines the grain of the Mg-2Zn-0.3Ca alloy, leading to the improvement of yield strength (82 MPa). While the coarse and discontinuous eutectic phases (α-Mg＋Ca2Mg6Zn3) accelerate the galvanic corrosion near the grain boundary. Sm microalloying promotes the formation of finely dispersed particles (Ca2Mg6Zn3-Sm) of the Mg-2Zn-0.3Ca alloy, reducing the electrode potential difference of the second phase and matrix. The Mg-2Zn-0.3Ca-0.4Sm alloy has the most moderate corrosion and compact protective layer in the three alloys, exhibiting excellent corrosion resistance (Pw = 1.26 mm·y−1) in vitro. The Mg-2Zn-0.3Ca-0.4Sc/Sm alloys are non-cytotoxic and promote cell proliferation.