1. © 3-Dimensional Modeling Of Laser Repetitive Pulse Heating: A Phase Change And A Moving Heat Source Considerations Yilbas, BS; Sami, M; AbuAlHamayel, HI ELSEVIER SCIENCE BV, APPLIED SURFACE SCIENCE; pp: 159-178; Vol: 134 King Fahd University of Petroleum & Minerals http://www.kfupm.edu.sa Summary Laser repetitive pulse heating may offer thermal integration at the workpiece surface during laser material processing. However, the condition for the thermal integration highly depends on the material response to successive laser pulses. In the present study, 3-dimensional laser heating of semi-infinite steel subjected to repetitive pulsation is considered. In modeling the process, an electron kinetic theory approach is employed and governing equations are derived. Since the governing equations derived are in the form of integro-differential equations, they do not yield analytical solutions. Therefore, the numerical method employing an explicit scheme is introduced to solve the governing equations. In the analysis, conduction and phase change processes are taken into account and the laser beam is considered as scanning the surface with a constant velocity. The repetitive pulses are introduced such that the ratio of successive pulse intensity to the first pulse intensity is kept constant and the cooling period between two consecutive pulses is also kept constant. To investigate the power intensity ratio on the resulting temperature profiles, three ratios are considered separately. Moreover, the condition for the thermal integration and isothermal heating are introduced. It is found that the temperature profiles do not follow the pulse profile and that thermal integration is possible for the low power intensity ratio considered in the present study. (C) 1998 Elsevier Science B.V. All rights reserved. References: Copyright: King Fahd University of Petroleum & Minerals; http://www.kfupm.edu.sa

2. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. © BLACKWELL FJ, 1990, ASME J HEAT TRANSFER, V11, P567 BRORSON SD, 1990, PHYS REV LETT, V64, P2172 HARRINGTON RE, 1967, J APPL PHYS, V38, P3266 MAJUMDAR J, 1980, J APPL PHYS, V51, P941 NETO OOD, 1994, J PHYS D APPL PHYS, V27, P1795 PARK HK, 1993, J HEAT TRANS-T ASME, V115, P178 QIU TQ, 1992, INT J HEAT MASS TRAN, V35, P719 SAMI M, 1996, OPT LASER ENG, V24, P319 SCHULZ W, 1993, J PHYS D APPL PHYS, V26, P1357 SIMON G, 1993, J PHYS D APPL PHYS, V26, P862 YILBAS BS, 1986, INT J ENG SCI, V24, P1325 YILBAS BS, 1993, JPN J APPL PHYS PT 1, V32, P5646 YILBAS BS, 1995, INT J MACH TOOL MANU, V35, P1047 YILBAS BS, 1995, JPN J APPL PHYS 1, V34, P6391 YILBAS BS, 1997, APPL SURF SCI, V108, P167 YILBAS BS, 1997, HEAT MASS TRANSFER, V32, P242 YILBAS BS, 1997, INT J HEAT MASS TRAN, V40, P1131 YILBAS BS, 1997, INT J MECH SCI, V39, P671 ZHANG HJ, 1990, J HEAT TRANS-T ASME, V112, P777 For pre-prints please write to: abstracts@kfupm.edu.sa Copyright: King Fahd University of Petroleum & Minerals; http://www.kfupm.edu.sa