Magnesium alloy strip produced by a melt-conditioned twin roll casting process

Melt conditioning by intensive shear was used prior to twin roll casting of an AZ91 magnesium alloy strip to promote heterogeneous nucleation and produce a refined and uniform microstructure without severe macro-segregation. The as-cast strip was then processed by homogenization, hot rolling and annealing and the microstructural behaviour during the downstream processing was examined and compared with the strip of the same alloy produced without melt conditioning. The melt conditioned strip after downstream processing displayed significantly improved mechanical properties with an average tensile elongation of ~16%, compared with ~10% for the strip produced without melt conditioning and the reported values of ~1.5-6.2% in the literature.