Contribution of the Self-Heating Method in the Characterization of the Fatigue Damage of Materials With Defects Resulting From Additive Manufacturing

Abstract

This paper investigates the ability of the self-heating method to characterize the fatigue behavior of 316L stainless steel produced by Laser Powder Bed Fusion. Nearly dense cylinders are built vertically using various process parameters corresponding to various volumetric energy densities. Fatigue specimens are then machined from these cylinders and polished. Fully reversed tension–compression fatigue tests (R = −1) are conducted. The self-heating method is used for the estimation of the fatigue limits. These fatigue limits are compared to results obtained from S-N curves in the high cycle regime. Whatever the set of process parameters, the self-heating curves show three distinct domains of heat dissipation. Thanks to microstructure analysis, fractographic observations, and correlations with S–N curves, these domains can be closely linked to damage mechanisms associated or not with defects.