Correlation between the crystallized structure of Mg67Zn28Ca5 amorphous alloy and the corrosion behavior in simulated body fluid.

• The uniform corrosion in SBF occurs on the surface of the amorphous alloy; in contrast, galvanic corrosion occurs on the crystallized samples, and the corroded surfaces of the alloys become more rugged with the increasing crystallization temperature due to galvanic corrosion. • With increasing crystallization temperature, different kind phases with different morphologies precipitate in Mg 67 Zn 28 Ca 5 amorphous alloy, which considerably influences its corrosion behavior. • It is found that the corrosion rate of the Mg 67 Zn 28 Ca 5 alloy in SBF shows a nearly linear relationship with the crystallized volume fraction. The corrosion behavior of Mg-Zn-Ca amorphous alloys in simulated body fluid is of academic and engineering interests since they are potential biomaterials. The influence of the crystallized structure of the Mg 67 Zn 28 Ca 5 amorphous alloy on the corrosion behavior in simulated body fluid (SBF) is investigated. The different crystallized structures were obtained by heating the amorphous sample to temperatures of 100 °C~300 °C. The results reveal that the amorphous Mg 67 Zn 28 Ca 5 alloy shows better corrosion resistance in SBF than partially crystallized samples, and homogeneous chemical corrosion occurs on the surface of the amorphous alloy. In contrast, inhomogeneous galvanic corrosion occurs on the surfaces of the partially crystallized Mg 67 Zn 28 Ca 5 sample; and the corroded surface becomes more rugged with increasing the crystallized temperature. The corrosion rate (V corr) of the Mg 67 Zn 28 Ca 5 amorphous alloy in SBF shows a nearly linear relation with the crystallized volume fraction (CVF), i.e., V corr = −8.38+96.23CVF, indicating that its corrosion behavior is readily tuned by crystallization. [ABSTRACT FROM AUTHOR]