FORMULATION OF A REACTIVE MATERIAL PASTE FOR ADDITIVE MANUFACTURING By Kelsay Neely Thesis Submitted to the Faculty of the Graduate School of Vanderbilt University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in Mechanical Engineering May, 2017 Nashville, Tennessee Approved: Alvin Strauss, Ph.D. Kevin Galloway, Ph.D. ACKNOWLEDGMENTS I would like to take this opportunity to thank Dr. Alvin Strauss and Dr. Kevin Galloway for their guidance and assistance throughout the research process. I would also like to thank my lab mates in the Vanderbilt University Welding Automation Lab, particularly Adam Jarrell and his willingness to be my ignition safety partner. I would like to thank all my friends who supported and encouraged me throughout the past two years, especially Lauren Branscombe and Courtney Mason. And finally, I would like to thank my family for supporting me, not just during the past two years, but for the past twenty-four years. ii TABLE OF CONTENTS Page ACKNOWLEDGMENTS .............................................................................................................. ii LIST OF TABLES ......................................................................................................................... iv LIST OF FIGURES .........................................................................................................................v Chapter I. INTRODUCTION .........................................................................................................1 Constructive Applications ..............................................................................................4 Destructive Applications ................................................................................................6 II. LITERATURE REVIEW ..............................................................................................8 III. THERMITE PASTE DEVELOPMENT......................................................................12 Binder Selection ...........................................................................................................12 Plaster Content .............................................................................................................16 Work Time ...................................................................................................................16 Molding ........................................................................................................................18 Porosity ........................................................................................................................19 Ignition .........................................................................................................................20 IV. IGNITION RESULTS .................................................................................................22 Speed of Ignition ..........................................................................................................25 V. ADDITIVE MANUFACTURING ..............................................................................26 Equipment ....................................................................................................................26 Slicing Software ...........................................................................................................28 G-Code .........................................................................................................................30 Printing Results ............................................................................................................31 VI. CONCLUSIONS..........................................................................................................34 VII. FUTURE WORK .........................................................................................................35 REFERENCES ..............................................................................................................................37 Appendix ........................................................................................................................................39 A. Ultimaker 2+ Data Sheet.....................................................................................................39 B. Purge G-Code .....................................................................................................................40 iii LIST OF TABLES Table Page 1. Selected Thermite Reactions and their Properties ...............................................................2 2. Binder Selection Summary ................................................................................................12 3. Plaster Composition Study Summary ................................................................................16 4. Ignition Speed ....................................................................................................................25 5. Ultimaker 2+ Summary......................................................................................................26 6. Basic Cura Settings ............................................................................................................28 7. Advanced Cura Settings .....................................................................................................29 iv LIST OF FIGURES Figure Page 1. Thermite Welding Diagram ...........................................................................................3 2. Thermite Welding on Railroad Tie ................................................................................4 3. Completed Thermite Weld .............................................................................................4 4. Thermite Weld of Copper Cables ..................................................................................5 5. Diagram of AN-M14 TH3 Incendiary Hand Grenade ...................................................6 6. Lawrence Livermore National Lab Work ......................................................................8 7. Los Alamos 3D Printed Explosive Cones ......................................................................9 8. Cold Spray Process Diagram .......................................................................................10 9. Thermite Proof of Concept ..........................................................................................14 10. Slag Porosity ................................................................................................................14 11. Partial Ignition of Thermite Sample ............................................................................15 12. Initial Plaster Curing Sample .......................................................................................17 13. Partially Cured Plaster Sample ....................................................................................18 14. Silicone Thermite Mold ...............................................................................................19 15. Standard Thermite Brick ..............................................................................................19 16. Thermite Cross Section ................................................................................................19 17. Thermite Ignition Setup ...............................................................................................20 18. Ignition Results #1 .......................................................................................................22 19. Ignition Results #2 .......................................................................................................23 20. Ignition Results #3 .......................................................................................................24 21. Ultimaker 2+ with Discov3ry ......................................................................................26 22. Discov3ry Attachment .................................................................................................27 23. Modified Start G-Code ................................................................................................30 24. Successful Printing of Thermite Paste .........................................................................31 25. Partial Print of Thermite ..............................................................................................32 26. Completed Thermite Print............................................................................................33 27. Slag of Printed Sample.................................................................................................33 28. Reactive Material Architectures ..................................................................................35 29. Constructive Thermite Applications ............................................................................36 v CHAPTER I INTRODUCTION The term “reactive materials” describes a class of materials that combines two or more nonexplosive solids that release high quantities of chemical and kinetic energies upon ignition [1]. In this document, the reactive material discussed is thermite. The thermite reaction is a reduction-oxidation reaction, characterized by a high reaction temperature, low gas production, and production of molten slag. The reaction supplies its own source of oxygen and, therefore, does not require exposure to air. Once the mixture is ignited, it will burn until all fuel is used, even underwater. This characteristic allows it