Effect of advancing direction on fatigue life of 316L stainless steel specimens treated by double-sided laser shock peening

Effect of Laser Shock Peening on surface properties and residual stress of Al6061-T6

Laser Shock Peening (LSP) is considered as an alternative technology to shot peening (SP) for the induction of compressive residual stresses in metallic alloys in order to improve their fatigue, corrosion and wear resistance. Since laser pulses generated by high-intensity laser systems cover only a small area, laser pulses are generally overlapped and scanned in a zigzag-type pattern to cover completely the surface to be treated. However, zigzag-type scanning patterns induce residual stress anisotropy as collateral effect. The purpose of this paper is to describe and explain, for the first time and with the aid of the numerical model developed by the authors, the influence of the scanning pattern directionality on the residual stress tensor. As an effective solution, the authors propose the application of random-type scanning patterns instead of zigzag-type in order to reduce the mentioned residual stress anisotropy.

Random-type scanning patterns in laser shock peening without absorbing coating in 2024-T351 Al alloy: A solution to reduce residual stress anisotropy

Aluminum (Al) and its alloys have widespread engineering applications because of their higher strength to weight ratio, ductility, and formability. However, in various applications, mechanical properties such as hardness, corrosion, wear, and fatigue resistance are prerequisite at near surface regions. Such localized modification without affecting the bulk phase can be performed by various surface-engineering approaches including electro-deposition, physical and chemical vapor depositions, thermal spraying, plasma spraying, and organic polymeric coatings. Delamination failure of such coatings from the substrate is often inevitable due to the difference in film-to-substrate elastic modulus associated with the aforementioned processes. Recently, researchers have adopted a new approach of laser surface engineering to modify the near surface regions of metallic substrate by laser beams resulting in superior mechanical properties with the formation of novel microstructures. In this article, the recent developm...

Laser-based Surface Modifications of Aluminum and its Alloys

On the fatigue performance of laser hybrid welded high Zn 7000 alloys for next generation railway components

https://hal.archives-ouvertes.fr/hal-01091371/document

Finite element analysis of laser shock peening of 2050-T8 aluminum alloy

Purpose – The purpose of this paper is to conduct a comparative study of the surface modifications induced by two different lasers on a 2050‐T8 aluminum alloy, with a specific consideration of residual stress and work‐hardening levels.Design/methodology/approach – Two lasers have been used for Laser shock peening (LSP) treatment in water‐confined regime: a Continuum Powerlite Plus laser, operating at 0.532 mm with 9 ns laser pulses, and near 1.5mm spot diameters; a new generation Gaia‐R Thales laser delivering 10 J‐10 ns impacts, with 4‐6mm homogeneous laser spots at 1.06 mm. Surface deformation, work‐hardening levels and residual stresses were analyzed for both LSP conditions. Residual stresses were compared with numerical simulations using a 3D finite element (FE) model, starting with the validation of surface deformations induced by a single laser impact.Findings – Similar surface deformations and work‐hardening levels, but relatively lower residual stresses were obtained with the new large 4‐6 mm impa...

Laser shock processing with two different laser sources on 2050‐T8 aluminum alloy

Laser shock peening (LSP) is an innovative surface treatment technique successfully applied to improving fatigue performance of metallic material. The specific characteristic of (LSP) is the generation of a low work-hardening and a deep compressive residual stresses mechanically produced by a laser-induced shock wave propagating in the material. The aim of this study is to analyse the residual stress distribution induced by laser peening in 2050-T8 aluminium alloy experimentally by the X-ray diffraction technique (method sin2Y) and numerically, by a finite element numerical modelling. A specific focus was put on the residual stress distribution along the surface of the impacted material.

Neila Hfaiedh

Papers

Finite element analysis of laser shock peening of 2050-T8 aluminum alloy

Laser shock processing with two different laser sources on 2050‐T8 aluminum alloy

Experimental and Numerical Analysis of the Distribution of Residual Stresses Induced by Laser Shock Peening in a 2050-T8 Aluminium Alloy