Application of Laser Shock Processing System by Underwater Irradiation (1064 nm) in Metal Surface

• Main Authors: Gomez-Rosas, G, Rubio-Gonzalez, C, Ocana, J L, Molpeceres, C, Porro, J A, Morales, M, Casillas, F J, Mora-Gonzalez, M, Pena-Lecona, F G
• Format: Conference Proceeding
• Language: English
• ISSN: 0094-243X
• DOI: 10.1063/1.2926803

Laser shock processing (LSP) is a technique for strengthening metals. This process induces a compressive residual stress field which increases fatigue crack initiation life, reduces fatigue crack growth rate and increases wear resistance of metals. We present a configuration and results in the LSP concept for metal surfaces treatments in underwater layer with constant thickness using laser irradiation at 1064 nm. A convergent lens is used to deliver 2, 5 J/cm2 in a 8 ns laser FWHM pulse produced by a Q-switch Nd:YAG Laser. Experimental results using a pulse density of 5000 pulses/cm2 and spots of 0, 8 mm to 1, 5 mm in diameter on AISI 1040 steel surfaces, Ti6Al4V surfaces, 304 Stainless Steel surface and 6061-T6 Aluminum surfaces are presented. A compressive residual stress distribution as a function of depth is assessed by the hole drilling method. High level compressive residual stresses are produced using a 1064 nm wavelength. This method can be applied for surface treatment of final metal products.