MSE 3050, Phase Diagrams and Kinetics, Leonid Zhigilei
homework #1 (page 1 out of 2)
1.
Calculate the molar enthalpy of pure iron at 1500 K and one
atmosphere pressure.
The molar heats of phase
transformations for iron are:
Δ
H
α→γ
= 670 J/mol;
Δ
H
γ→δ
= 840 J/mol;
Δ
H
δ→
liquid
= 13770 J/mol.
The constant pressure heat capacities
of different phases of pure iron are:
c
P
α
= 17.5 + 24.8
×
10
3
T
J/mol K
c
P
γ
= 35.5
J/mol K
c
P
δ
= 43.9
J/mol K
c
P
liquid
= 41.84
J/mol K
Use the phase diagram to estimate the temperatures of phase
transformations at 1 atm (or find an accurate value in a reference book)
Plot schematically enthalpy vs temperature at one atmosphere pressure
for pure iron in the temperature range from 298K to 1500K.
In the plot
show the values of temperatures of the phase transformations and the
values of enthalpies at T = 298 K and T = 1500 K.
γ
Fe
α
Fe
δ
Fe
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View Full DocumentMSE 3050, Phase Diagrams and Kinetics, Leonid Zhigilei
homework #1 (page 2 out of 2)
3. Calculate heat of formation of Al
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 Spring '12
 Zhigilei

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