Predictive assessment and experimental characterization of the influence of irradiation parameters on surface deformation and residual stresses in laser-shock-processed metallic alloys

Abstract

Although valuable experimental work has been performed in order to explore the optimum conditions of application of the treatments and to assess their capability to provide enhanced mechanical properties, there is little work done on the theoretical prediction of these optimum parameters. In the present paper, a model is presented to provide an estimation of the residual stresses and surface deformation in order to see the influence of the different parameters in the process. The influence of pulse duration, pulse pressure peak, spot radius, number of shots, overlapped shots and material properties are studied. The great influence of 3D deformation effects in the process is clearly shown as one of the most important limiting factors of the process traditionally neglected in previous literature. Additionally, from the experimental point of view, in the present paper a summary is provided of different results obtained from the most recent LSP experiments carried out by the authors along with some conclusions for the assessment of LSP technology as a profitable method for the extension of fatigue life in critical heavy duty components.

Induction of Engineered Residual Stresses Fields and Associate Surface Properties Modification by Short Pulse Laser Shock Processing

“…The observation of these results clearly leads to the consideration of the LSP technique as really effective and controllable within wide limits for the induction of engineered residual stresses fields in critical components through modification of specific mechanical and chemical material properties, especially mechanical fatigue and corrosión resistance. The effect has been widely demonstrated by the authors in simple geometries [11][12][13][14] and, with the aid of the developed calculational tools [9][10], can be readily applied to arbitrary component geometries.…”

“…More recently, on the basis of the commercial availability of new powerful láser sources able to provide intensities exceeding the GW/cm level, a new intense research effort aims to develop the LSP technology from an industrial point of view [5][6][7][8]. The authors have made previous contributions to the field showing initial results of their developments [9][10][11][12][13][14][15][16][17].…”

Induction of through-thickness compressive residual stress fields in thin Al2024-T351 plates by laser shock processing

“…A similar kind of problems has been analized for the case of Shot Peening by Guagliano [5] With the aid of the calculational system developed by the authors (SHOCKLAS®; see [6][7]), the analysis of the problem of LSP treatment for induction of residual stress fields for fatigue life enhancement in relatively thin sheets in a way compatible with reduced overall workpiece deformation due to spring-back self-equilibration has been envisaged. Numerical results directly tested against experimental results have been obtained confirming the critical influence of the laser energy and irradiation geometry parameters.…”

Laser Shock Processing: an emerging technique for the enhancement of surface properties and fatigue life of high-strength metal alloys

“…Only very few contributions (see, for example, references [10][11][12][13] from the authors) have been devoted to this coupled analysis with the aim to correlate laser incidence and interaction material-geometry parameters to final thermomechanical effects resulting in treated specimens.…”