Fluidity of Mg-Al alloys and the effect of alloying elements

Fluidity tests of Mg-Al (-RE/Si) alloys were conducted and the effect of al loying composition and superheat on fluidity was studied using fluidity tes t spirals. The microstructure of the fluidity spirals was examined. The flo w mechanisms of the magnesium alloys were analysed and found to be separate d into two stages: fluidity with superheat and fluidity with zero superheat . Different solidification modes in magnesium alloys led to two different f low mechanisms. Flow between primary particles existed. For the studied all oying ranges (Al (6 to 12 %), RE (1 to 3 %) and Si (0.3 to 1.5 %)), fluidit y increases with the increase of the alloying element content. Alloying inf luences the fluidity mainly through a change of the solidification mechanis m.