1. Shady Taghizadeh, University of Massachusetts, Lowell, MA Major: Plastics Engineering “DREAM” Research Experience

2. Areas of Research/Study Thermal Spray Technology: –Background. –Processes being used. Preparation of feedstock powders: –Materials. –Processing. Differential Scanning Calorimetry [DSC]: –Principles of technique. –Application to current project. –Results & interpretation.

3. Some Important Applications Aerospace/Transportation Electronics Bio-Medical

4. The Thermal Spray Family Tree Rod Wire Powder Feedstock Materials Heat Source Acceleration Impact Splatting & Cooling

5. HVOF Combustion Spray Process Characteristics Jet TemperatureGenerally >2,500 °C Jet SpeedTypically >1,000 m/s Gas Flow Rate400-1,100 slm Particle Speed200-1,000 m/s Powder Feed Rate2-50 g/min 76 – 230 mm100 – 300 mm [H 2 ]

6. HVOF Spraying System…In Operation

7. High Velocity Oxy-Fuel (HVOF) Spraying System

8. My Research Goals: Characterization and preparation of polymeric & polymer-ceramic composite powders for HVOF spraying. Characterization of ceramic reinforced polymer powders & coatings. Processing & Characterization Techniques: Ball-Milling. DSC: Differential Scanning Calorimetry.

9. Ball-Milling - Rotate for ~48 hrs on Ball-Milling machine Ceramic Balls + Pure Nylon11 Ball Mill + 10 % Silica (7 nm)

10. Ball-Milling Calculations Example: 10 Vol. % SiO 2 in 90 Vol.% Nylon-11; Total amount required = 250 g Formula: WFSiO 2 = = WF Nylon11= 1- WF SiO 2 = 1- 0.18 = 0.81 x 100 = 81% *WF= Weight Fraction To find the weight of each sample: SiO 2 = total amount of mixture * WF SiO 2 = 250 g* 0.18 = 45 g Nylon 11 = total amount of mixture * WF Nylon11 = 250 g * 0.81 = 203 g

11. Differential Scanning Calorimetry [1] Empty Aluminum Pan Aluminum Sample Pan Thermocouples Heaters

12. Differential Scanning Calorimetry [2] Aluminum Sample Pan Empty Aluminum Pan

13. Differential Scanning Calorimetry [3] Inflection Point

14. Differential Scanning Calorimetry [4]

15. Calculating %Crystallinity Given: 21% gives = 87.5 J/g from manufacturer obtained from graph Formula: Value obtained from the graph % Crystallinity in material

16. Results: Sample Melting Temp% Crystallinity Nylon 11 60 µm (Powder) 180 ºC21% Nylon 11 60 µm (Coating) 185 ºC16% Nylon 11 60 µm + 10 % vol. 7nm Silica (Powder) 186 ºC13% Nylon 11 60 µm + 10 % vol. 7nm Silica (Coating) 183 ºC15%

17. Future Work: Characterization of powders through SEM Using Horiba to determine particle size distribution. Polishing and mounting of samples.

18. References http://www.thailandtourism.gr/images/Thai-Airways- aircraft.jpghttp://www.thailandtourism.gr/images/Thai-Airways- aircraft.jpg http://www.theworkshop.net/images/welcome/automotive.j pghttp://www.theworkshop.net/images/welcome/automotive.j pg http://www.csie.ntu.edu.tw/~ling/europe/packing/photos/el ectronics.jpghttp://www.csie.ntu.edu.tw/~ling/europe/packing/photos/el ectronics.jpg http://www.cvm.ncsu.edu/docs/images/Fig2_fullsize.jpg http://www.psrc.usm.edu/macrog/dsc/htm Milan Ivosevic’s thesis [include title, date etc.] Elena’s Petrovicova’s Thesis : Structure and Properties of Polymer Nanocomposite Coatings Applied by the HVOF Process (July 1999).

19. Acknowledgements NSF for the REU “DREAM” Program Department of Materials Science and Engineering CPPM Kishore Tenneti (Polymer Processing Lab.) Dr. Richard Knight Milan Ivosevic Dustin Doss Varun Gupta

20. Thank You & Any Questions?