70 Prakt. Met. Sonderband 38 (2006) 
Fig.4: Light optical micro- 
graph of remelted and 
gravity cast AG5.7S51.9 
showing primary o-den- 
drites (coarser than in 
Fig.2) and regular “Chinese 
script” Mg»2Si structures 
(black) with about 10 um 
distance in between. 
{UL ym 
UJ Jn 
TEE - _ 
Fig.5: LOM of remelted and gravity cast AG5.7S2.4 showing in a) coarser a. dendrites and 
Mg2Si structures than in Fig.3a; the marked area is enlarged in b) demonstrating the 
different size classes of the interdendritic structures (submicron to 20um) 
FE 
hete 
a 
whic 
Fig.6: LOM of gravity cast AG5.8S5.6 showing in a) a. dendrites and a higher volume not s 
fraction of Mg,Si structures than in Fig.3; b) shows a star-like Mg,Si structure, Fe-rich view 
“needles” (marked Fe) and fine structured eutectic areas (marked eut). preci 
level 
The highly alloyed, gravity cast AG4.9S8.4 sample is depicted in Fig.7a after solution treat Cros: 
ment. The chinese script Mg,Si became rounded, and the fine eutectic spheroidized. Fig. wher 
7b-f show images of the same region depicting all 3 phases: Mg2Si, eutectic Si and AlFeSi. appe