Papers by Author: Bruno Courant

Abstract: This study investigates the heat management in Duplex Stainless Steel (DSS) wall specimens produced by the Wire Arc Additive Manufacturing (WAAM), by optimizing the thermal cycles during their construction. A reduction in the inter-pass time was found to induce heat accumulation, which causes wall flaring, affects the ferrite/austenite balance, and leads to a reduction in the hardness of the mechanical part produced by DSS. In contrast, the introduction of an external cooling system enhances the geometry and helps control the temperature and microstructure of the produced parts, thereby achieving the required hardness. Therefore, the use of the external cooling system enables the production of parts with desirable mechanical properties in a shorter time.

Abstract: A two-level homogenisation approach is applied to the micro-mechanical modelling of the elasto-plasticity of polycrystalline materials during various strain-path changes. The model is tested by simulating the development of intragranular strains during different complex loads. Mechanical tests measurements are used as a reference in order to validate the model. The anisotropy of plastic deformation in relation to the evolution of the dislocation structure is analysed. The results demonstrate the relevance of this approach for FCC polycrystals.