1/12 Computational Thermodynamics and Kinetics Team 1 Group A Brittany Brandon Katharine Hickey Kim Larrabee Francisco Martinez Randi Patterson

2/12 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.

3/12 Purpose To create a magnesium alloy with higher creep resistance with numerous applications such as cars, airplanes, and laptops.

4/12 Background Information Face Centered Cubic Body Centered Cubic MgZn 2 Hexagonal Laves Structure (C14)

5/12 Phase Diagram Explanation Ca 2 Mg 5 Zn 5 Ca 2 Mg 6 Zn 3 CaMg 2 Zn Ca 2 Mg 5 Zn 13 CaMgZnTotal / 11 =.18 6 / 11 =.55 3 / 11 =.27 CaMgZnTotal / 20 = / 20 = / 20 =.65 CaMgZnTotal / 12 =.17 5 / 12 =.42 5 / 12 =.42 CaMgZnTotal 1214 ¼ =.25 2 / 4 =.50 ¼ =.25 CaMgZnTotal / 3 = / 3 =.33 2 / 3 = / 3 =.33 0 / 3 = / 3 = / 3 =.33 2 / 3 =.67 0 / 3 = 0.0

6/12 Procedure 1.Sanding 240 grit sandpaper 400 grit sandpaper 600 grit sandpaper 800 grit sandpaper 1200 grit sandpaper 2.Polishing Polishing cloths 1.0 µ silicon in methanol 0.3 µ silicon in methanol Polishing machine 3.Clamp the samples Stainless steel cylinder Stainless steel screws Stainless steel slugs 4.Vacuum seal samples Glass cylinder Glass blowing machine Fiberglass Vacuum pump

7/12 Procedure 4.Place in furnace Furnace Thermo-calc (software program) 5.Remove Samples Quench samples 7.Mount samples Epoxy Resin Hardener 8.Cut samples in cross- sections Diamond tipped saw 9.Repeat steps 1 and 2 10.Examine using optical microscopy Optical microscope

8/12 Results 320°C, 9 days, –Diffusion occurred 325°C, 9days –Diffusion occurred Diffusion distance is approximately the same 343°C sample was inconclusive ________________________ Factors Influencing Diffusion: –Oxidation –Polishing Quality –Amount of Pressure –Time Constraints

9/12 Conclusion Evidence shows that diffusion did occur. Hypothesis could not be proven or disproved due to time constraints. Future research will be needed.

10/12 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.

11/12 Any Questions?

12/12 Dr. Zi-Kui Liu (Dr.) Yu Zhong Cyndi Freeman Fail Jody Markley Jerome Crawford Kevin Harman Upward Bound Math and Science Staff Acknowledgements