THE INFLUCE OF CA ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF A MG-9LI-2AL SHEET

摘要

Mg-9wt.%Li-2wt.%Al with 0.1～1wt.% Ca alloys were cast and rolled to sheet at room temperature. Effect of Ca on microstructure and mechanical properties of the sheet is studied in this study. Uniaxial tension tests are carried out at room temperature. The rise of tensile strengthen and yield strength of the sheets can be 11.84% and 11.5%, respectively, when Ca content being 1wt.%. Elongation descends largely with Ca content rise, which is considered as the presence of Al_2Ca phase. Ca can refine grains and the effect of refinement is the evidentest while Ca content being 0.1 wt. %. It is clarified that adsorption of Ca on the grain boundary makes grains refined and changes the mechanical properties of sheets.