Abstract
This is a study on alloying method in adding zirconium to magnesium and its alloys, by use of ZrCl4, ZrCl4+KCl, ZrCl4+KCl+NaCl, Mg-Zr master alloy and ZrCl4+alkali metal haloids. Regarding alloying efficiency, no difference was found between thesealloying agents. But, it was found that Mg-Zr master alloy and ZrCl4+KCl+NaCl were better than others in practice, due to the fact that they made less chloride contamination in magnesium alloy castings.
Zirconium alloying agents should be added while the molten alloy remained at low temperature, in order to minimize iron, which inhibits the alloying zirconium, soluting into magnesium from steel crucible.
The content of zirconium and rare earth metals get decreased as the magnesium alloy containing them is repeatedly remelted, it is therefore, necessary to vivify the zirconium content. In this operation, the use of ZrCl4 decreases the content of rare earth metals in the alloy, while Mg-Zr master alloy, ZrCl4+(RE) Cl3, ZrCl4+NaF, or ZrCl4+MgO can minimize the loss of rare earth metals.
