The effects of the addition of cerium on workability of magnesium were studied. The workability of magnesium alloys having various contents of cerium was evaluated by the total elongation of test pieces in tension test and by the working limit of plates in cold rolling, at which the occurrence of cracks appeared on the side faces of the plates.
The alloy containing 0.2wt.% of Ce exhibited the largest elongation in tension test and also the highest working limit in cold rolling. The workability of magnesium was generally improved by the addition of cerium, the effects and would be due to the occurrence of deformation bands caused by compressive strain. The results showed that in case of pure magnesium a few number of deformation bands were observed being concentrated in limited regions; while, in alloys containing cerium the deformation bands were uniformly distributed throughout the pieces. It was also observed that the deformation bands started to from at the regions near grain boundaries and gradually spread into the grains.
At the final stage of deformation, the formation of cracks was associated with deformation bands, and then they developed along the bands.