BUP23 - PrAKTra

Due to its high torque density, the transverse flux machine is suitable as an emission-free direct drive in electric vehicles. Given the complex geometry combined with rapid innovation cycles, additive manufacturing processes are ideally suited for creating prototypes of this kind of electric motors. However, classic plastics are reaching their limits for this application. In contrast, aluminum oxide ceramics have the ideal prerequisites due to their dielectric and thermal properties.

Aim

The aim of the project is to improve the mechanical properties and surface quality of additively manufactured ceramic components by developing a binder system and a post-processing process. The suitability is investigated using the example of the transverse flux machine.

A challenge in additive manufacturing of ceramics (Fused Deposition of Ceramic, FDC) with filaments is the resolution and the staircase effect due to the printing process. The so-called green body is produced with common filament 3D printers. The ceramic part is then created by a thermal post-treatment (debinding and sintering). Post-processing on the sintered part is only feasible at great expense, so the project is focussed on post-processing of the green part.

Approach

• Determination of a suitable recipe for the extrusion compound: the requirements for the binder cannot be met with polymers commonly used for Fused Deposition Modeling (FDM), so a binder system with PVB, PEG and additives is  investigated. The formulations are evaluated based on key properties.
• Investigation of the extrusion behavior to determine suitable printing parameters: for this purpose, a sample part is designed, which is derived from the electromagnetic design of a transverse flux machine. The post-processing of the green part is carried out with a dip-coating process.
• Investigation of the sintered components and evaluation of the suitability of the process and material for the selected application    

Rapid innovation cycles are made possible due to additional design options and the rapid implementation of new designs.