Advertisement

Measuring Spallation Strength of Epoxy by Laser Spallation Technique

  • Sarthak S. Singh
  • R. Kitey
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

The laser spallation technique in combination with Michelson interferometry is employed to estimate the spallation strength of epoxy film. The epoxy layer of thickness 160 μm is deposited onto the microscopic glass (MG) substrate. The specimens are subjected to high amplitude short duration stress waves, developed by the pulsed laser ablation of sacrificial absorbing layer, deposited at the back surface of the substrate. The complex interaction of rarefaction waves with the mode converted tensile pulse from the free surface of the film develops high magnitude tensile region. For sufficiently high stresses spallation is observed in the top part of the epoxy layer. Profilometric analysis confirms spallation in the epoxy layer while the MG/epoxy interface remains intact. Interferometric measurements exhibit distinctly spaced fringe patterns. The temporal span of the wave arrivals confirms that the fringes correspond to the longitudinal and the rarefaction waves. Based on the space-time wave travel analysis the spallation depth is predicted which is in excellent agreement with the profilometric observations. By employing dynamic wave propagation analysis in combination with the interferometric data, the spallation strength of epoxy is estimated to be 260 ± 15 MPa.

Keywords

Thick film Rarefaction waves Spallation Michelson interferometer Micro-cracks 

References

  1. 1.
    Kanel, G.I., Razorenov, S.V., Bogatch, A., Utkin, A.V., Fortov, V.E., Grady, D.E.: Spall fracture properties of aluminum and magnesium at high temperatures. J. Appl. Phys. 79(11), 8310–8317 (1996)CrossRefGoogle Scholar
  2. 2.
    Field, J.E., Walley, S.M., Proud, W.G., Goldrein, H.T., Siviour, C.R.: Review of experimental techniques for high rate deformation and shock studies. Int J Impact Eng. 30(7), 725–775 (2004)CrossRefGoogle Scholar
  3. 3.
    Zaretsky, E., Perl, M.: The response of glass fibers reinforced epoxy composite to an impact loading. Int. J. Solids Struct. 41(2), 569–584 (2004)CrossRefGoogle Scholar
  4. 4.
    Gupta, V., Argon, A.S., Cornie, J.A., Parks, D.M.: Measurement of interface strength by laser-pulse-induced spallation. Mater. Sci. Eng. A. 126, 105–117 (1990)CrossRefGoogle Scholar
  5. 5.
    Wang, J., Weaver, R.L., Sottos, N.R.: A parametric study of laser induced thin film spallation. Exp. Mech. 42(1), 74–83 (2002)CrossRefGoogle Scholar
  6. 6.
    Kitey, R., Sottos, N.R., Geubelle, P.H.: A hybrid experimental/numerical approach to characterize interfacial adhesion in multilayer low-κ thin film specimens. Thin Solid Films. 519(1), 337–334 (2010)CrossRefGoogle Scholar
  7. 7.
    Barker, L.M.: Laser interferometry in shock wave research. Exp. Mech. 12(5), 209–215 (1972)CrossRefGoogle Scholar
  8. 8.
    Gilath, I., Eliezer, S., Dariel, M.P., Kornblit, L., Bar-Noy, T.: Laser induced spall in aluminum and copper. Le Journal de Physique Colloques. 49(C3), C3–191 (1988)CrossRefGoogle Scholar
  9. 9.
    Asay, J.R., Shahinpoor, M. (eds.): High-Pressure Shock Compression of Solids, Chapter-2. Springer Science & Business Media, New York, NY (2012)Google Scholar
  10. 10.
    Barker, L.M., Hollenbach, R.E.: Shock-wave studies of PMMA, fused silica, and sapphire. J. Appl. Phys. 41(10), 4208–4422 (1970)CrossRefGoogle Scholar
  11. 11.
    Wang, J., Weaver, R.L., Sottos, N.R.: Laser-induced decompression shock development in fused silica. J. Appl. Phys. 93(12), 9529–9536 (2003)CrossRefGoogle Scholar

Copyright information

© The Society for Experimental Mechanics, Inc. 2019

Authors and Affiliations

  1. 1.Department of Aerospace EngineeringIndian Institute of TechnologyKanpurIndia

Personalised recommendations