Magnesium And Magnesium Alloys, Grain Refinement

Owning to its better properties in many aspects than other alloys, the wide application of Magnesium alloys is becoming inseparable. The key problem of Magnesium application is its poor forming ability , so it is very important to find an effective grain refiner for Magnesium alloys.In this paper, the grain refiner to pure Magnesium, AZ31 and Mg-RE alloys are studied by observing their metallurgical structures under as-cast or annealing state. The results demonstrate that : for pure Magnesium, Al-5Ti-0.3C Al-5Ti-lB Ce and Nd are the ones that can refine the grains , and as the adding amounts o~ these grain refiners increase, the grains become smaller; for AZ31 Magnesium alloys, the grains with Al-5Ti-0.3C Ce and Nd are refined obviously. The best contents are 1.2%(Al-5Ti-0.3C) 0.8%Ce and 0.8%Nd; for Mg-RE alloy, the adding of Zr makes grains very fine. A: last, the mechanical characters of materials with refined structures are tested. It proves that both plasticity and the strength are improved.