Microstructure, mechanical and corrosion properties of novel Mg-Sn-Ce alloys produced by high pressure die casting

The aim of this study was to investigate the effect of adding 1, 2 and 4% wt of cerium on the microstructure, mechanical and corrosion properties of high pressure die casting (HPDC) Mg-4Sn alloys. Microstructure analyses of the alloys were carried out using X-Ray Diffraction (XRD) and Scanning Electron microscopy (SEM). The corrosion behaviors were determined with the potentiodynamic polarization and immersion tests in Hanks Balanced Salt Solution (HBSS), which is used as the artificial body fluid. The microstructural results showed that the addition of Ce to the main alloy creates new intermetallic phases (Ce₅Sn₄ and MgSnCe). In addition, Ce addition provided effectively the grain refinement of the alloys. While the hardness and yield strength of the Mg-4Sn alloy enhanced continuously with increasing Ce content, the tensile strength and elongation reached up to 2% wt. The corrosion resistance of the main alloy was improved by the addition of 1% wt of Ce. However, the Ce content, which is more than 1% wt decreased corrosion resistance.