14th International Conference on Shot Peening

Fatigue performance at 550°C of shot peened Inconel 718 additively manufactured by Laser-Powder Bed Fusion (L-PBF)

Charles Bianchettia, Pascale Kanouté a, Cécile Davoine a, Ariel Morel a, Thomas Gheno a, Sébastien Merciera, Louise Toualbia

DMAS, ONERA, Université Paris Saclay, F92322, Chatillon, France

charles.bianchetti@onera.fr

Introduction

Metal additive manufacturing is a disruptive technology that is likely to replace some traditional manufacturing processes. However, this process creates undesirable high surface roughness [1], porosity [2], and tensile residual stress [3]. These side effects imply that as-built (AB) test pieces have drastic inferior fatigue life in comparison with that of the conventional counterparts [1, 4]. Consequently, additive manufactured parts must undergo surface finish to increase their fatigue life.

Shot peening is a process used to increase fatigue life. Bagherifard et al., 2018 [5] showed for the AlSi10Mg alloy that the roughness of the AB parts decreased after shot peening, which consequently increased the fatigue strength by 270% in comparison with the AB condition. However, the effect of shot peening on fatigue life of IN718 additively manufactured is yet to be studied at elevated temperature.

Objectives

The objective of the present study is to evaluate fatigue properties enhancement by shot peening of the IN718 manufactured by Laser-Powder Bed Fusion (L-PBF) and to understand the close interaction between surface treatments and oxidation.