Computational Thermodynamics and Kinetics

1
Computational Thermodynamics and Kinetics

• Team 1 Group A
• Brittany Brandon
• Katharine Hickey
• Kim Larrabee
• Francisco Martinez
• Randi Patterson

2
Introduction

• What is Computational Thermodynamics and
  Kinetics?
• Computational Thermodynamics is the discipline by
  which phase diagrams are generated through
  analysis of the basic thermodynamic properties of
  metals.
• Kinetics is the branch of science that is
  concerned with the rates of change in processes.
  
• What is diffusion?
• The movement of particles from a region of higher
  concentration to a region of lower concentration.
• Hypothesis
• The experimental results will prove the
  existence of three new phases consisting of
  magnesium, calcium, and zinc.

3
Purpose

• To create a magnesium alloy with higher creep
  resistance with numerous applications such as
  cars, airplanes, and laptops.

4
Background Information
Body Centered Cubic
Face Centered Cubic
MgZn2 Hexagonal Laves Structure (C14)
5
Phase Diagram Explanation
Ca Mg Zn Total
2 5 5 12
2/12 .17 5/12 .42 5/12 .42
Ca Mg Zn Total
2 6 3 11
2/11 .18 6/11 .55 3/11 .27
Ca Mg Zn Total
2 5 13 20
2/20 0.1 5/20 .25 13/20 .65
Ca Mg Zn Total
1 2 1 4
¼ .25 2/4 .50 ¼ .25
Ca Mg Zn Total
0 1 2 3
0/3 0.0 1/3 .33 2/3 .67
CaMg2Zn
Ca2Mg6Zn3
1 0 2 3
1/3 .33 0/3 0.0 2/3 .67
1 2 0
1/3 .33 2/3 .67 0/3 0.0
Ca2Mg5Zn13
Ca2Mg5Zn5
6
Procedure

• Sanding
• 240 grit sandpaper
• 400 grit sandpaper
• 600 grit sandpaper
• 800 grit sandpaper
• 1200 grit sandpaper
• Polishing
• Polishing cloths 1.0 µ silicon in methanol
  0.3 µ silicon in methanol
•   Polishing machine

• Clamp the samples
• Stainless steel cylinder
• Stainless steel screws
• Stainless steel slugs
• Vacuum seal samples
• Glass cylinder
• Glass blowing machine
• Fiberglass
• Vacuum pump

7
Procedure

• Place in furnace
• Furnace
• Thermo-calc (software program)
• Remove Samples
• Quench samples
• Mount samples
• Epoxy Resin
• Hardener
• Cut samples in cross-sections
• Diamond tipped saw
• Repeat steps 1 and 2
• Examine using optical microscopy
• Optical microscope

8
Results

• 320C, 9 days,
• Diffusion occurred
• 325C , 9days
• Diffusion occurred
• Diffusion distance is approximately the same
• 343C sample was inconclusive
• ________________________
• Factors Influencing Diffusion
• Oxidation
• Polishing Quality
• Amount of Pressure
• Time Constraints

9
Conclusion

• Evidence shows that diffusion did occur.
• Hypothesis could not be proven or disproved due
  to time constraints.
• Future research will be needed.

10
Further Research

• View samples under an SEM to show the number of
  phases that exist.
• To determine certain characteristics of the
  phases, a wide variety of microscopes will be
  used .

11
Any Questions?
12
Acknowledgements

• Dr. Zi-Kui Liu
• (Dr.) Yu Zhong
• Cyndi Freeman Fail
• Jody Markley
• Jerome Crawford
• Kevin Harman
• Upward Bound Math and Science Staff