1. Analysis of Thermally Sprayed Nylon Splats Jeremy Baldoni DREAM Fellow 7/28/05 Advisors: Mentors: Dr. Richard Knight Dr. Richard A. Cairncross Mr. Milan Ivosevic Mr. Varun Gupta

2. Schematic of Thermal Spray 3. Material coats substrate with finite number of small splats, solidifies 2. Heat and gas flow turn the material into a stream of fast moving molten droplets 1. Material starts as a solid (powder)

3. Applications of Thermal Spray 1 Industries Aerospace Automotive Marine Printing Infrastructure Purposes Wear Prevention Thermal Insulation Corrosion Resistance

4. High Velocity Oxy-Fuel (HVOF) HVOF particles have: Less “dwell time” Greater kinetic energy than in traditional T.S. 2

5. Why HVOF with Nylon 11? Why HVOF with Nylon 11? HVOF is powerful yet practical in the field Nylon 11 is versatile and useful Currently, dangerous VOCs are used as Nylon 11 solvents 3 Philadelphia’s Benjamin Franklin Bridge

6. My Project: Splat Analysis Isolated nylon splat on flat glass (fried egg) 3D Computer Modeling SEM, Optical Inspection Analysis of HVOF Sprayed Nylon Splatting Behavior Understanding T.S. of Nylon Could Make Potential Applications a Reality

7. Single vs. Multiple Passes (Optical) Variety of splat shapes, sizes Difficult to see splat:substrate and splat:splat interface Flat glass 200x: Single Pass Flat glass 200x: Three Passes

8. Cross Sections of Splats (Optical) 1000x Polished Steel One splat is flat, one is rounded--why?

9. Polished Steel, GB50 Steel Cross Sections (Optical) Polished Steel 1000x Steel Grit Blasted with 50 Mesh Grit (GB50)1000x Grit blasted specimen appears to allow for greater mechanical splat:substrate interlocking

10. Glass: Several Splats (SEM) As Delivered GlassGlass GB120

11. Glass: Single Splats (SEM) Smooth GlassGlass GB120

12. GB120 Glass Zoom What is the extent of splat:substrate interlocking?

13. Steel: Several Splats (SEM) Polished GB120 GB50 GB12

14. Steel: Single Splats (SEM) Polished GB50 GB120 GB12

15. Computer Modeling: Flow-3D Flat Substrate Simple computer generated roughened substrates Actual GB steel substrate representation- Zygo

16. Flow-3D Examples Preliminary splat images—several variables ignored Good stepping stone to more realistic roughnesses

17. Next Steps: Roughness Project Better SEM images of splats on rough substrates Cross section images of each substrate roughness Computer modeling on increasingly realistic substrate roughness representations Comparison of actual splats to model predictions Use model to predict beyond experimental results Ultimate goal: determine how nylon needs to be sprayed so that it can become widely used

18. Citations 1. J.R. Davis (editor): Handbook of Thermal Spray Technology, ASM International, Materials Park, OH, 2004. 2. Technical Paper Thermal Spraying, Air Products and Chemicals Inc. accessed July 15, 2005, http://www.airproducts.com/Products/CylinderGases/MAXX/ThermalSpraying/thermalspraying_tec hpaper.htm. http://www.airproducts.com/Products/CylinderGases/MAXX/ThermalSpraying/thermalspraying_tec hpaper.htm 3. Benjamin Franklin Bridge, Philadelphia, A View On Cities, accessed July 18 2005, http://www.aviewoncities.com/gallery/showpicture.htm?key=kveus1065&dir=bridges&tpe=cat. http://www.aviewoncities.com/gallery/showpicture.htm?key=kveus1065&dir=bridges&tpe=cat