Speaker
Description
Additive Manufacturing (AM) technologies provide new opportunities to enhance some piece-producing processes in the industry: AM offers the possibility to produce complex-shaped parts that could require multiple manufacturing stages. Moreover, microstructures from Laser Powder Bed Fusion (LPBF) can heavily differ from microstructures usually obtained through traditional processes, showing extremely fine cells caused by the rapid cooling.
In this work, several LPBF preforms were constructed along different directions in order to study the anisotropic properties inherited by the LPBF technology. Then, the as-built samples were cold rolled at different deformation rates. Two 316L powders that produce two different microstructures were used: one exhibiting columnar grains and the other quasi-equiaxed ones. Optical microscopy (OM) and scanning electron microscopy along with electron backscatter analyses (SEM-EBSD) were used to determine the microstructural evolutions. Tensile testing was carried out to determine the mechanical properties.
The first results show that the LPBF 316L is ductile while being more resistant than the traditional wrought 316L. In addition, the orientation of the building direction (BD) compared to the rolling direction (RD) seems to have an influence on the material properties during cold rolling. Indeed, mechanical twins were observed when the BD is collinear to the RD while slip bands are present when the BD is orthogonal to the RD, even if one of the studied microstructure is almost isotropic with quasi-equiaxed grains and almost no texture.
The final goal of this study is to analyse the potentialities of integrating the LPBF technology in the conventional manufacturing processes. This integration would then simplify and enhance key parts production, especially in the nuclear industry.