Origins of enhanced prismatic slip in Mg alloys: Atomic scale investigation

Using lightweight alloys (alloys with high strength to weight ratio) is essential in transportation industries as it reduces the overall weight of the vehicles and their fuel consumption. Mg is the lightest structural metal with density of about one-fourth of that of steel, respectively. However, high purity Mg are rarely used for structural applications due to their very low yield strength. Adding alloying elements has been proven to be an effective method in increasing the strength. By addition of solutes to the pure metal and by proper thermomechanical processes, material gains additional strength due to various mechanisms. However, despite decades of investigation on the mechanical properties of Mg based alloys, there remain many issues to be solved that inhibit their wider use as alternative alloys to steels. Brittleness of due to the inactivity of non-basal slip systems such as prismatic slip are main issues in Mg. This thesis will focus on solute strengthening mechanisms in Mg alloys. Specifically, at the first part of this research we will use computational methods to study the prismatic slip in Mg. Prismatic slip is a non-basal slip and its activation can lead to significant improvement in formability of Mg alloys.