In this work, the influence of the additions of Zn, Zr and Ce-Mischmetall on the casting, indirect extrusion processing, microstructural development and resulting mechanical properties of Mg and Mg-alloys were investigated. It was found that grain size of the cast alloys is controlled by a grain growth factor (Q) mechanism. Q predicts the grain size of the cast billet, a parameter which influenced strongly the deformation response of the alloy during extrusion. Zener-Hollomon parameter (Z) was determined using process variables. Z correlated alloy dependent deformation variables during...