1. Thermodynamic Modeling of the
Platinum-Yttrium system
Madeline Boyer
Undergrad presentation
Summer 2011
1

2. Outline
• Brief introduction of summer goals
• Summary of Pt-Y system
– Literature review
– Discussion of experimental data
• Calculations of enthalpy values
• Thermodynamic Data and ThermoCalc
– Learning process
– Setting up ThermoCalc, challenges
• Modeling Results
• Future goals
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3. My history with 304 Phases
Diffusion couples (Mg-Al) with Lauren Skrabski
Central South University
Resulted in a paper with Laura Jean Lucca
3

4. Madeline’s Timeline 2011
June July August
Literature [1] Milestone 1: Completing
review the Literature review
Thermo calc [2]:Moving from Mg-Ni system to Pt-Y
modeling of Learning
ThermoCalc
Pt-Y
Modeling
of Pt-Y [3] Finish Pt-Y diagram
system
1st Batch
[6]: 1000hrs [7]:2000hrs
2nd Batch
Lauren‘s Steel [8]:begin
[11]:1000hrs [12]:2000hrs
[9]:100 hrs
[10]:200hrs
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5. Motivation for this work
• Usefulness for others in the lab
• Possible work with first-principles in the future
• Contributing to the ONR project
• Pt-Y system has not been modeled
• Learning project
• Stepping stone for undergraduate thesis
• Polymer modeleing in ThermoCalc as senior project
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6. Literature Review
• Drawn
based on
Er-Pt
system
Palenzona, Bull. Alloy Phase Diag., 1990 6

7. Literature Review Discussion
• Previous work:
– Holcombe (1976): melting point of the eutectic
– Moffatt (1971): Pt-Er system
– Vorona (1983): confirmed the existence of 10
compounds at 600 °C
– Mediema (1975): calculated 3 different enthalpy
of formation values at .25 composition Y in Pt, .5
and .75
– Hellwig (1978): Experimental Gibbs energy for two
compounds
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8. Limited experimental enthalpy of
formation values found in the literature
Compounds Composition Mediema DfH Hellwig DfH
(kJ-mol-atom) (kJ-mol-atom)
Pt5Y 0.167 -64.33
Pt3Y 0.25 -87.864 -96.71
Pt2Y 0.333
Pt4Y3 0.429
PtY 0.5 -121.34
Pt4Y5 0.556
Pt3Y5 0.625
PtY2 0.667
Pt3Y7 0.7
PtY3 0.75 -66.94
L.Hellwig, Kernforschungszentrum Karlsruhe,.1978
A.R Miedema, Journal of Less Common Metals,.1976
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9. Used experimental values to create a
convex hull as starting point for modeling
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10. ThermoCalc: Macros, Pops, and
Parrots
• Friendly Thermodynamics with Alyson
• Macro files and Pop files
• Optimizing and Modeling
– Brief summary of Models used
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11. Entropy Calculations for the
8 other compounds
• ∆G = ∆H - ∆S*T
• ∆G = A + B*T
• Hellwig(1978)
– ∆fGPt5Y = -385.97 + 5.4e10-3*T kJ/mol
– ∆fGPt3Y = -386.83 + 19.6e10-3*T kJ/mol
• As a starting point, calculate A/B ratio for all
compounds based on known experimental
data
L.Hellwig, Kernforschungszentrum Karlsruhe,.1978
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12. As part of the learning process for
ThermoCalc, learn to plot with no parameters
Liquid
bcc
fcc
hcp
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13. Creating a setup.tcm and defining
the compounds
• Macro file set up: Declaring all compounds
• Example:
PT5Y
2 SUBLATTICES, SITES 5: 1
CONSTITUENTS: PT : Y
G(PT5Y,PT:Y;0) - 5 H298(FCC_A1,PT;0) –
H298(HCP_A3,Y;0) = + 5*GHSERPT + GHSERYY
+ V1 + V2*T
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14. Liquid Parameters
L(LIQUID,PT,Y;0) = +V41+V42*T
L(LIQUID,PT,Y;1) = +V43+V44*T
L(LIQUID,PT,Y;2) = +V45+V46*T
G
A B
Alyson Lieser, “Friendly Thermodynamics” (2011) 14

15. ThermoCalc Setup: Pop file
ACM
1
ACM
2
APR1 APR2 APR3 APR4
APR5
AEP2 APR6
APR7
AEPT APR8
AEYY
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16. First step of modeling with two
compounds from experimental data
Liquid
bcc
Pt5Y
Pt3Y
fcc
hcp
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17. Current modeling of the Pt-Y system
Liquid
PtY
Pt5Y
Pt3Y
bcc
fcc
hcp
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18. Future Goals
• Scaling entropy values down to get correct
temperatures for invariant reactions
– Focus on eutectic reactions
• New challenges
– Possible modeling of another system in the fall
– Working towards possible modeling with
polymers.
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19. Acknowledgements
I would like to thank so very much:
Chelsey Zacherl and Alyson Lieser
And also
Brian VanLeeuwan, Bi Cheng Zhou, Arkapol
Saengdeejing, and Dr. Liu
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21. Calculated Enthalpy values
Compound Composition (percent Y) Estimated DH (kj-mol)
Pt5Y 0.167 -64.33
Pt3Y 0.25 -96.71
Pt2Y 0.333 -106.5
Pt4Y3 0.429 -115.5
PtY 0.5 -121.34
Pt4Y5 0.556 -111.5
Pt3Y5 0.625 -97
PtY2 0.667 -86.5
Pt3Y7 0.7 -78.5
PtY3 0.75 -66.94
Red number: Experimental
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22. Entropy Values
Composition Calculated
Compounds (Percent Y) Estimated Enthalpy entropy value
Pt5Y 0.167 -64.33 0.0009 A/B = ratio
Pt3Y 0.25 -96.71 0.0049
Pt2Y 0.333 -106.5 0.002335
Pt4Y3 0.429 -115.5 0.002532
PtY 0.5 -121.34 0.00266
Pt4Y5 0.556 -111.5 0.002445
Pt3Y5 0.625 -97 0.002127
PtY2 0.667 -86.5 0.001897
Pt3Y7 0.7 -78.5 0.001721
PtY3 0.75 -66.94 0.001468
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23. Current model parameters
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