| Abstract Scope |
The lightest structural magnesium alloys suffer from limited strength and corrosion resistance. A cost-effective solution is to develop a rare-earth-free high-strength Mg-Ca alloy by adding tin (Sn). After casting and homogenising for 24 hours at 380°C, the alloy was artificially aged for 6, 12, and 18 hours at 200°C. Vickers microhardness, optical microscopy, SEM with EDS analysis, XRD, XRF, and corrosion test in a 3.5% NaCl solution were carried out. The intermetallic phase in the alloy formed along the grain boundary. Sn induces the formation of second phases, which precipitate while heat-treated. The Mg-Sn precipitates formed prevent the dislocation movement, which results in a hardness increment. The formation of MgCaSn second phases and the dissolution of Sn in the matrix stabilizes the oxide protective film of corrosion products and thus enhances the corrosion behaviour, which was concurred with trends observed in Bode and Nyquist plots. |