Binary SolidLiquid Phase Diagram

1
Binary Solid-Liquid Phase Diagram

For the vanadium carbon phase diagram shown
below
? L
L gr
L
ß L
? gr
a L
?
ß ?
a
ß
V3C2 ß
a ß
V3C2 ?
V3C2

• Determine the empirical formulas of the single
  compound present in this diagram and indicate
  whether it melts congruently or decomposes and
  the temperature at which it does so. AMV 50.94
  g/mol and AMC 12.01 g/mol.
• ( 13.6 g ) / ( 12.01 g/mol ) 1.132 mols C
• ( 86.4 g ) / ( 50.94 g/mol ) 1.696 mols C
• V1.696C1.132 V1.500C1.000 gt V3C2
  decomposes at 1319 ?C

2

• b. On the diagram label the one-phase solutions
  with a single Greek letter. As you proceed
  across the diagram from left to right, label each
  of the successive one phase regions with the
  other Greek letters. Use the letters in the
  order
• a, b, g, d, q, f
• You may not need as many letters as I have given
  you.
• c. On the diagram label the region where the melt
  exists with an L.
• On the diagram in each of the two phase regions
  indicate the two phases that are in equilibrium
  with each other in that region, using the
  appropriate Greek letters. For simplicity call
  the phase on the right of the diagram at 30
  carbon, graphite.
• Label each line of three phase equilibrium as
  either a eutectic or peritectic line and indicate
  the three phases that are in equilibrium along
  this line by writing a reaction for either the
  eutectic or peritectic equilibrium.
• 1648 ?C eutectic a ß -----gt L
• 2190 ?C peritectic L ? -----gt ß
• 1319 ?C peritectic V3C2 -----gt ß ?
• 2605 ?C eutectic L -----gt ? gr