The Ternary System MgO-Al t O % -SiO v 



309 



Table 11. 



Quenchings which determine melting temperatures of various compositions 



within field E-1-2-D ; Primary phase is Si0 2 . 



lpositio 



n. Weight 



Per cent 



Temp. 



Time in 



Phases present 



MgO 



AL0 3 



Si0 2 





hours 





20-0 



15-0 



650 



1455 



•5 



Glass 









1450 



•5 



Glass + Si0 2 



110 



220 



670 



1445 



•5 



Glass 









1435 



•5 



Glass + SiO, 



20-0 



18-0 



62-0 



1355 



•5 



Glass 









1352 



•5 



Glass + Si0 2 



150 



150 



700 



1530 



•5 



Glass 









1500 



•5 



Glass + Si0 2 



Table 12. 



Quenchings which determine melting temperatures of various compositions 



within field D-2-3-7-C; Primary phase is AL0 3 .Si0 2 . 



n positio 



n. Weight 



Per cent 



Temp. 



Time in 



Phases present 



MgO 



A1 2 3 



Si0 2 





hours 





15-0 



32.0 



530 



1460 



10 . 



Glass 









1457 



1.0 



Glass + AIA-SiOo 



10-0 



240 



66-0 



1438 



1-0 



Glass 









1435 



10 



Glass 4- Al 2 3 -Si0 2 



160 



40-0 



44-0 



1550 



.25 



Glass 









1525 



.25 



Glass 4- Al 2 3 .Si0 2 



14-5 



36-5 



490 



1550 



•25 



Glass 









1525 



■25 



Glass 4- Al 2 3 .Si0 2 



100 



300 



600 



1550 



•25 



Glass 







- 



1525 



• 25 



Glass 4- Al 2 3 .Si0, 



Table 13. 



Quenchings which determine melting temperatures of various compositions 



within field 1-2-3-4-5; Primary phase is the ternary 



compound (cordierite). 



Composition Weight Per cent Temp. Time in Phases present 



Glass 



Glass 4- cordierite 



Glass 



Glass 4- cordierite 



Glass 



Glass 4- cordierite 



Glass 



Glass 4- cordierite 



Glass 



Glass 4- cordierite 



Glass 



Glass -+- cordierite 



Glass 



Glass 4- cordierite 



Glass 



Glass 4- cordierite 



Glass 



Glass 4- cordierite 



Glass 



Glass 4- cordierite 



Glass 



Glass 4- cordierite 



MgO 



A1 2 3 



Si0 2 





hours 



160 



34-0 



50-0 



1460 



10 









1457 



1 







20-0 



230 



57-0 



1400 

 1375 





5 



5 



18-0 



30-0 



52-0 



1450 

 1425 





5 

 5 



25.0 



23-0 



52-0 



1370 

 1365 





5 

 5 



20-0 



250 



55.0 



1415 

 1400 





5 

 5 



150 



300 



55-0 



1460 

 1450 





5 



5 



230 



200 



57-0 



1375 





5 









1350 



1 







15-0 



27-0 



58-0 



1450 

 1425 





5 

 5 



200 



20-0 



600 



1365 

 1340 



1 





 5 



150 



230 



620 



1425 

 1400 





5 

 5 



110 



230 



660 



1450 

 1440 



1 





 5 



