This presentation was made as a course requirement by Deepak Rajput at the University of Tennessee at Knoxville.

1. Laser Shock Peening of Bulk Metallic Glasses – Part 1 Center for Laser Applications UT Space Institute Tullahoma, TN 37388-9700 http://www.utsi.edu Midterm Presentation MSE516: Mechanical Metallurgy Deepak Rajput Email: [email_address] / Web: http://drajput.com

3. Team Members Dr. Hofmeister Director, CLA UT Space Institute Alexander Terekhov Deepak Rajput Dr. Lino Costa Dr. Xiaoxuan Li Center for Laser Applications Kate Lansford

9. Peening: Generation of Compressive Stresses Cont. Shot peened gear Metal Improvement Company Paramus, New Jersey Problem: Leaves surface dimpling

10. Peening: Generation of Compressive Stresses Cont. Laser Peening or Laser Shock Peening (LSP): “ A process that induces residual compressive stresses on the surface of a component due to shock waves produced by plasma” “ Four times deeper than that obtainable from a conventional Shot Peening process” Prototype Laser Peening machines were developed in the 1970s .

11. Laser Shock Peening Historical background: William I. Linlor Hughes Research Laboratories Malibu, California Linlor, W.I. (1962) “Plasma Produced by Laser Bursts” Bull. Am. Phys. Soc. 7, 440 Ready, J.F., (1963) “Development of Plume of Material Vaporized by Giant Pulse Laser”, Appl. Phys. Letters 3 (1), pp 11-13 # giant pulse investigation, carbon plume speed in air Linlor, W.I. (1963) “Ion Energies Produced by Laser Giant Pulse”, Appl. Phys. Letters 3 (11), pp 210-211

14. Laser Shock Peening Process layout Taken from Metal Improvement Company website (http://www.metalimprovement.com/laser_peening.php)

15. Laser Shock Peening Research @ Purdue University Dr. Yung C. Shin (Professor) Laser-Assisted Materials Processing Laboratory (LAMPL) School of Mechanical Engineering Purdue University, West Lafayette, Indiana

16. Laser Shock Peening Example: Robot controlled LSP Taken from Metal Improvement Company website (http://www.metalimprovement.com/laser_peening.php)

17. Laser Shock Peening Laser Shock Peening of 6061-T6 Aluminum Alloy Rubio-Gonzalez C. et al. (2004), “Effect of Laser Shock Processing on Fatigue Crack Growth and Fracture Toughness of 6061-T6 Aluminum Alloy”, Mat. Sci. Eng. – A, 386: 291-295

18. Laser Shock Peening Laser Shock Peening of 6061-T6 Aluminum Alloy Rubio-Gonzalez C. et al. (2004), “Effect of Laser Shock Processing on Fatigue Crack Growth and Fracture Toughness of 6061-T6 Aluminum Alloy”, Mat. Sci. Eng. – A 386: 291-295 Fatigue crack growth rates with and without LSP under different pulse densities

19. Laser Shock Peening Laser Shock Peening of 6061-T6 Aluminum Alloy Rubio-Gonzalez C. et al. (2004), “Effect of Laser Shock Processing on Fatigue Crack Growth and Fracture Toughness of 6061-T6 Aluminum Alloy”, Mat. Sci. Eng. – A 386: 291-295 Load-displacement curves to determine fracture toughness

22. Planned Experiment Laser Shock Peening of Cu-based Bulk Metallic Glasses Suggested Laser: Excimer laser ( λ = 337 nm) Planned Layout:

24. Questions ?

25. Thank You for your patience