Study of the influence of the ferrite additive manufacturing process on mechanical and magnetic properties

Traditional methods of manufacturing ceramic parts include costly processes such as slip casting, pressing or injection molding; they require specific equipment and expertise. When small quantities of ceramic parts, or prototypes, with specific properties are required, manufacturers are still forced to make costly investments. In addition, traditional manufacturing processes restrict design freedom and make it difficult to create internal channels, overhangs or lattice structures, for example. 3D printing opens up new prospects for innovation in the field of technical ceramics, by offering low-cost machines and opening up the field of possibilities for the design of complex parts impossible to obtain with molding methods.
This is the background to the subject of this thesis, on a ceramic material of interest to the CEA: (Ni-ZnFe2O4) ferrite. The CEA masters the manufacture of this material by traditional methods of powder pressing followed by sintering, but would like to extend its skills by producing parts with more complex geometries, with a reduced time between the design stage and the manufacture of a first prototype.
The work will involve optimizing the microstructure of ferrite implemented using Fused Deposition Modeling (FDM) 3D printing technology, then measuring mechanical and magnetic properties, as well as magneto-elastic effects. An analysis will be carried out to correlate the relationship between microstructure and material properties. The results will be compared with the conventionally developed material. This will highlight the influence of the manufacturing process on properties. Finally, a part with a complex geometry will be developed with the aim of understanding the difficulties associated with the change of scale. This stage will be accompanied by an initial assessment of the robustness of the process.