Autors: Mihalev, M. S., Hardalov, C. M., Christov, C. G., Leiste, H.
Title: Microstructural Characterization of Thin Laser Bonded Coatings based on Transitional Metal Oxides Powder
Keywords: laser, laser bonding, transition metal oxide, catastrophic oxidation, Raman scattering, X-Ray diffraction

Abstract: Laser bonding is a process of preparing coatings of oxides powder, mainly from transition metals, which are irradiated by a power laser. The oxide powder undergoes different physical and chemical transitions and a layer over the substrate with different optical and microstrucural properties is produced. In this work a coating of MoO3 has been produced by laser bonding. Micro-Raman scattering and X-Ray Powder Diffraction (XRD) have been used to estimate the chemical compound of the produced coatings, as well as their microstructure phases. It has been demonstrated that in addition the initial a-orthorhombic MoO3 the monoclinic b-phase is observed. The chemical compound undergoes also changes – in both spectra (Raman and XRD) the presence of new less-stable oxide Mo4O11 can be found, but no MoO2 in every structural form. The results obtained show, that new oxides appear. The new oxides build stable chemical bond to the substrate and have complex catalytic an re-oxidation properties.

References

  1. Steen, M. W., 1994, Laser material processing, 2. ed., London UK, Springer Verlag
  2. Edited by Collin E. Webb, 2004, Handbook of Laser Technology and Applications, Brostol, UK, Institute of Physics Publishing
  3. Mihalev, M., Ch. Hardalov, C. Christov, H. Leiste, 2013, A Study of Hardness and Adhesion of Laser Bonded MoO3 Layers on Stainless Steel, Sozopol, 7-11 September 2013, <Sozopol>, TU-Sofia
  4. DAVID JOHN YOUNG, 2008, High Temperature Oxidation and Corrosion of Metals, Amsterdam, NE, Elsevier
  5. Birks, M, G. H. Maier, F. S Petit, 2006, Introduction to High Temperature Oxidation of Metals, Second Edition, New York, Cambridge University Press
  6. Brandon, D, , W. D. Kaplan, 2008, Microstructural Characterization of Materials, Second Edition, Chichester, UK, Wiley
  7. www.wikipedia.org, 2013, Raman Scattering, <http://en.wikipedia.org/wiki/Raman_scattering>, Дата на последен преглед (Last accessed on): 27.11.2013
  8. pcpdf – computer program with XRD pattern database
  9. Lalik, E, W. I. F. David, P. Barnes, and J. F. C. Turner, 2001, Mechanisms of Reduction of MoO3 to MoO2 Reconciled?, J. Phys. Chem. B, Volume 105, pp. 9153-9156
  10. Camacho-Lуpez, M.A.,, L. Escobar-Alarcуn, M. Picquart, R. Arroyo, G. Cуrdoba, E. Haro-Poniatowski, 2011, Micro-Raman study of the m-MoO2 to a-MoO3 transformation induced by cw-laser irradiation, Optical Materials, Volume 33, pp. 480–484
  11. Dieterle, M. and G. Mestl, 2002, Raman spectroscopy of molybdenum oxides: Part II. Resonance Raman spectroscopic characterization of the molybdenum oxides Mo4O11 and MoO2, Phys. Chem. Chem. Phys., Volume 4, pp. 822-826

Issue

XXIII National scientific symposium with international participation Metrology and Metrology Assurance 2013, September 9-13, 2013, Sozopol, Bulgaria: Proceedings, pp. 219-225, 2013, Bulgaria,

Full text of the publication

Вид: пленарен доклад в международен форум