Investigation of the Effect of La and Ti Addition to Mg–4Sn–2Al Alloy on Microstructure, Mechanical and Corrosion Properties

In this study, Mg–4Sn–2Al alloy by weight was produced by gravity casting under a controlled atmosphere. The effect of alloying elements added to this alloy on microstructure, mechanical, and corrosion properties was investigated. Alloying elements were chosen as 2% La, and 0.15% Ti by weight. During the research, SEM/EDS, XRD, tensile, % elongation, hardness, hardening exponent, anisotropy coefficients, fracture surfaces, corrosion rates, and corrosion microstructures of the alloys were investigated. According to the results obtained, Mg–4Sn–2Al–2La and Mg–4Sn–2Al–0.15Ti alloys showed higher mechanical properties compared to Mg–4Sn–2Al alloy. While the ultimate tensile strength for Mg–4Sn–2Al alloy was 131 MPa, it increased to 159 MPa for Mg–4Sn–2Al–2La alloy and 163 MPa for Mg–4Sn–2Al–0.15Ti alloy. At the same time, the strain hardening exponent and anisotropy coefficients of Mg–4Sn–2Al alloy increased with the addition of La and Ti. This shows that the formability of the alloy is improved. In addition, there was not much difference in the hardness values of the alloys. At corrosion rates, the lowest corrosion rate was 11.68 mpy in Mg–4Sn–2Al–0.15Ti alloy, 29.69 mpy in Mg–4Sn–2Al–2La alloy and the highest corrosion rate was 46.60 mpy in Mg–4Sn–2Al alloy. The addition of La and Ti decreased the corrosion rate of Mg–4Sn–2Al alloy.