14th International Conference on Shot Peening

Microstructure evolution during direct laser peening of metals in femtosecond and picosecond regimes

L. Rousseaua, b, A. Nakhoula, b, A. Rudenkob, c, X Sedaob, d, N. Peillona, J. P. Colombierb, C. Mauricea, G. Blanca, A. Borbélya, N. Faureb, G. Kermouchea

Mines Saint-Etienne, University of Lyon, CNRS, UMR 5307 LGF, Centre SMS, F-42023, Saint-Etienne, France b UJM-St-Etienne, CNRS, Institute of Optics Graduate School, Laboratoire Hubert Curien UMR 5516,F-42023 Saint-Etienne, France c Arizona Center for Mathematical Sciences and College of Optical Sciences, University of Arizona, Tucson, Arizona 85721, USA

d GIE Manutech-USD, 42000 Saint-Etienne, France

Introduction

Ultrafast laser was recently used to modify the surface integrity and peen the surface region of aluminium based alloy 2024-T351 without a sacrificial layer [1]. Plastic deformation is considered to be created by an ultrafast laser-induced pressure wave [2]. The correlation between laser parameters and modified surface properties was interpreted by the complex interplay between laser excitation, material relaxation, and pressure waves.

Objectives

We aim to achieve a comprehensive understanding of the physical phenomenon behind femtosecond laser peening and to be able to predict the optimal peening parameters for different metals (Al, Ti). We would like to link residual stresses to metal properties – such as crystal structure, heat conductivity, electric conductivity.