Ultrafine Grain Development AZ91 Magnesium Alloy Through Friction Stir Processing: Mechanical Properties and Corrosion Resistance

Abstract

This study introduces the Friction stir processing (FSP) of AZ91 magnesium alloy for grain refinement with a view to improve the mechanical and corrosion properties. The results of microstructural characterization show a considerable change in the grain size from 49.49 µm to 4.91 µm after FSP. This refining contributes to mechanical performance improvement, tensile strength increase (250MPa to 310MPa), yield strength increase (150MPa to 190MPa), elongation increase (8% to 12%) showed strong improvement and ductility. Moreover, corrosion resistance has improved significantly, reducing the corrosion rate from 0.5 mm / year to 0.2 mm / year. The study goes on to show how FSP parameters, (i.e rotational and traverse speeds), affects the material enhancement and also establishes optimum conditions.  The study produces evidence that FSP offers significant refinement in the microstructure of AZ91. Furthermore, researchers remarked how this technique improves its mechanical properties and corrosion resistance. As such, FSP is suitable for lightweight structural applications. This means that FSP could be utilized in aerospace, automotive and marine industries where their weight reduction and corrosion resistance would be useful. The study shows that employing FSP would be a powerful technique to enhance the performance of magnesium alloys.