Inclusions in Al-Mg alloy castings and their filtering

Abstract

Effects of such defects as inclusions and porosities on mechanical properties of A1-10%Mg alloy were studied using a filter. Most of inclusions in a molten metal are MgO. Filtering through a bed of Al₂Os balls of 3 to 5 mm in diameter or MgO flakes effectively removes inclusions. The refining grade of molten metal is determined from defects area in the fracture surface. The defects area correlates with ultimate tensile strength, elongation and impact values. The larger the defect is, the lower the mechanical properties fall. When inclusions are small in size and number, observation of the polished surface using a quantitative television microscope is valid in estimation of quality for Al-Mg alloys.