Metal Additive Manufacturing Conference - MAMC 2022

In recent years, additive manufacturing has become increasingly relevant for producing magnetic materials due to higher demands for miniaturisation and complex-shaped magnet parts. With laser powder bed fusion (LPBF), magnet parts of the Fe-Cr-Co system can be produced with notable shape accuracy. The chemical composition can be modified directly in the printing chamber with the in-situ alloying technique. With this novel method, complex alloys can be produced with a chemical composition accustomed to each specific case of application. The next logical step in this direction is the development of a functionally graded structure with in- situ alloying which is the aim of this study.
The approach for the development of this novel process has been specifically designed for the ORLAS Creator, the 3D printer used. Three alloys of the Fe-Cr-Co system have been chosen as base materials which have been provided as stocks of elemental powder mixtures. To each of these stock materials, four different alloying elements (Ti, Al, Nd and Mo) have been added with the aim to create a defined chemical gradient in discrete steps. To validate the accuracy of the process, the resolution of chemical segregation between and at the interfaces of regions of different concentrations of alloying elements has been determined by SEM- EDS investigations. Additionally, different printing parameters known to produce sound parts of the material have been chosen to be printed simultaneously to investigate their influence on the accuracy at the interfaces between the regions.