Development of wrought Mg alloys, particularly in sheet form, is essential to support the
growing interest for lightweight components in the automotive industry. However, development of
Mg alloy sheets has been quite slow due to the complexity of sheet production originated from limited
deformability of Mg. In this respect, twin-roll strip casting, a one-step processing of flat rolled
products, can be an alternative for the production of Mg alloy sheets. In this study, AZ31 and
experimental ZM series alloys are twin-roll strip cast into 2 mm thick sheets. The microstructure of
the as-cast AZ31 alloy sheet consists of columnar zones near the roll side and equiaxed zones in the
mid-thickness region. On the other hand, as-cast ZM series alloy sheets show equiaxed dendritic
structure through the thickness of sheet. These alloys were subjected to various thermo-mechanical
treatments and their tensile properties were evaluated. Twin-roll strip cast AZ31 alloy in H24
condition has equivalent yield and tensile strengths with similar ductility compared to commercial
ingot cast AZ31-H24 alloy, indicating that twin-roll strip casting is a viable process for the fabrication
of Mg alloy sheets. The experimental ZM series alloys have a large volume fraction of fine dispersoid
particles in the microstructure, resulting from the beneficial effect of twin-roll strip casting on
microstructural refinement. It has been shown that the experimental ZM series alloys have superior
tensile properties compared to commercial ingot cast AZ31-H24 alloy, suggesting the possibility of
the development of new wrought Mg alloy sheets by twin-roll strip casting.
Effect of heat treatments on the microstructures and tensile properties of an ultrafine-grained Al-Zn-Mg alloy processed by ECAP