GLY 4200 Name KEY
Homework Exercise 5
Binary Phase Diagrams - Eutectic Behavior
1. On the attached diagram, outline each liquidus line in green, each solidus line in
brown.
2. Starting at points A and B, trace the cooling behavior of each melt down to 700°C.
Show the path followed by the liquid in red, the path followed by the solid in blue. Then
answer the following questions for:
2A: a) At what temperature does the first crystal appear? 960°C
b) What is the composition of the first crystal? NaF
c) At what temperature does the first crystal of NaMgF
3
appear? 830°C
d) At what temperature does the liquid disappear? 830°C
e) What is the composition of the final liquid phase? 50% NaF, 50% NaMgF
3
f) What is the composition of the final solid mixture? (Phases present and percent of
each)
80% NaF, 20% NaMgF
3
2B: a) At what temperature does the first crystal appear? 1020°C
b) What is the composition of the first crystal? NaMgF
3
c) At what temperature does the first crystal of NaMgF
3
appear? 1020°C
d) At what temperature does the liquid disappear? 1000°C
e) What is the composition of the final liquid phase? 25% MgF
2
, 75% NaMgF
3
f) What is the composition of the final solid mixture? (Phases present and percent of
each)
10% MgF
2
, 90% NaMgF
3
