| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1428480 | Materials Science and Engineering: C | 2015 | 7 Pages |
•Effects on the bio-corrosion behaviour are illustrated.•Both second phase volume fraction and grain size are key factors.•Balanced secondary phase volume fraction and grain size are desirable.
The bio-corrosion behaviour of Mg–3Zn–0.3Ca (wt.%) alloy in simulated body fluid (SBF) at 37 °C has been investigated using immersion testing and electrochemical measurements. Heat treatment has been used to alter the grain size and secondary phase volume fraction; the effects of these on the bio-corrosion behaviour of the alloy were then determined. The as-cast sample has the highest bio-corrosion rate due to micro-galvanic corrosion between the eutectic product (Mg + Ca2Mg6Zn3) and the surrounding magnesium matrix. The bio-corrosion resistance of the alloy can be improved by heat treatment. The volume fraction of secondary phases and grain size are both key factors controlling the bio-corrosion rate of the alloy. The bio-corrosion rate increases with volume fraction of secondary phase. When this is lower than 0.8%, the dependence of bio-corrosion rate becomes noticeable: large grains corrode more quickly.
