DOI QR코드

DOI QR Code

Influence of Surface Roughness on Morphology of Aluminum Alloy After Pulsed-Laser Irradiation

펄스 레이저 조사 후 알루미늄 합금의 표면상태에 대한 표면 거칠기의 영향

  • Received : 2011.04.18
  • Accepted : 2011.07.13
  • Published : 2011.09.01

Abstract

The objective of this study is to investigate the influence of surface roughness on the morphology of aluminum 6061-T6 alloy after irradiation with a Nd:YAG pulsed laser. The test specimen was prepared by a polishing process using a diamond paste ($1{\mu}m$) and emery polishing papers (#100, #220, #600, #2400) to obtain different initial surface roughness. After irradiation with ten pulsed-laser shots, the surface morphology was examined by using scanning electron microscopy (SEM), optical microscopy (OM), and atomic force microscopy (AFM). The diameter of the melted zone increased with the surface roughness because the multiple reflections and absorption of the laser beam occurred on the surface because of the surface roughness, so that the absorptance of the laser beam changed. This result was verified using the relative absorptance calculated from the diameter of the melted zone with the surface roughness and the diameter increased with the average surface roughness.

Keywords

Pulsed-Laser;Average Surface Roughness;Diameter of Melted Zone;Absorptance

References

  1. Cui, C. Y., Cui, X. G., Zhang, Y. K., Luo, K. Y., Zhao, Q., Hu, J. D., Liu, Z. and Wang, Y. M., 2010, "Microstructure and Microhardness Analysis of the Hexagonal Oxides formed on the Surface of the AISI 304 Stainless Steel after Nd:YAG Pulsed Laser Surface Melting," Applied Surface Science, Vol. 256, pp. 6782-6786. https://doi.org/10.1016/j.apsusc.2010.04.089
  2. Chang, C. C., Chou, C. P., Hsu, S. N., Hsiung G. Y., and Chen, J. R., 2010, "Effect of Laser Welding on Properties of Dissimilar Joint of Al-Mg-Si and Al-Mn Aluminum Alloys," Journal of Materials Science & Technology, Vol. 26, No. 3, pp.276-282.
  3. Son, Y. M., Jang, J. H., Joo, B. D., Yim, H. S. and Moon, Y. H., 2009, "Characterization of Direct Laser Metal Forming Technology for the Restoration of Mold Surface," Trans. of the KSME A, Vol. 33, No. 7, pp. 681-686. https://doi.org/10.3795/KSME-A.2009.33.7.681
  4. Cho, S. H., Park, J. K., Kim, J. G., Chang, W. S., Choi, D. S. and Whang, K. H., 2010, "Ultra-precision Machining using a Femtosecond Laser," Journal of the Korean Society for Precision Engineering, Vol. 27, No. 6, pp. 17-23.
  5. Kim, K. W., Lee, J. H., Suh, J. and Cho, H. Y., 2007, "Finite Element Analysis for Prediction of Band Shape of Nd:YAG Laser Fillet Welding," Trans. of the KSME A, Vol. 31, No. 8, pp. 839-846.
  6. Lim, H. T., Lee, M. H., Kim, P. K., Park, J. B. and Jeong, S. H., 2009, "Enhancement of Surface Hardness of Stainless Steel by Laser Peening," Journal of KSLP, Vol. 12, No. 3, pp. 18-22.
  7. Nam, G. J., K Kim,. W., Hong, J. U., Lee, J. H., Suh, J. and Cho, H. Y., 2006, "Finite Element Analysis of Nd:YAG Pulse Laser Welding for AISI 304 Stainless Steel Plate," Trans. of the KSME A, Vol. 30, No. 4, pp. 428-434. https://doi.org/10.3795/KSME-A.2006.30.4.428
  8. Perry, T. L., Werschmoeller, D., Li, X., Pfefferkorn, F. E. and Duffie, N. A., 2009, "Pulsed Laser Polishing of Micro-milled Ti6Al4V Samples," Journal of Manufacturing Processes, Vol. 11, pp. 74-81. https://doi.org/10.1016/j.jmapro.2009.10.001
  9. Bergström, D., Powell, J. and Kaplan, A. F. H., 2007, "The Absorptance of Steels to Nd:YLF and Nd:YAG Laser Light at Room Temperature," Applied Surface Science, Vol. 253, pp. 5017-5028. https://doi.org/10.1016/j.apsusc.2006.11.018
  10. Kruapech, S. and Widjaja, J., 2010, "Laser Range Finder using Gaussian Beam Range Equation," Optics & Laser Technology, Vol. 42, pp. 749-754. https://doi.org/10.1016/j.optlastec.2009.11.020
  11. Mannion, P. T., Magee, J., Coyne, E., O'Connor, G. M. and Glynn, T. J., 2004, "The Effect of Damage Accumulation Behaviour on Ablation Threcholds and Damage Morphology in Ultrafast Laser Micromachining of Common Metals in Air," Applied Surface Science, Vol. 233, pp. 275-287. https://doi.org/10.1016/j.apsusc.2004.03.229
  12. Bonelli, M., Miotello, A. and Mosaner, P., 2002, "Morphological Changes Induced on Aluminum Surfaces by Excimer Laser Irradiation," Applied Surface Science, Vol. 186, pp. 211-215. https://doi.org/10.1016/S0169-4332(01)00764-4