The main project objective is to increase the power density of electric machines by 40% and to increase their efficiency by 5%point by developing multi-material additive manufacturing (MM-AM). AM4EM will especially focus on combining two materials during printing: electrically/magnetically conductive and an insulator. The project will move technology from TRL2 to TRL4. AM4EM defined several subobjectives:
1. Develop, manufacture and validate innovative parts for electrical machines leveraging on MM-AM, of two types:
a. Novel winding geometries for electrical machines based on Cu as conducting material and ceramic as electrical insulation material. The parts should be able to withstand temperatures >180°C, and the ceramic should have sufficient thermal conductivity. Finally, the individual wires should be electrically isolated and resistant to voltage spikes.
b. Innovative stator and rotor core based on Fe-Si or other magnetic material (e.g. Fe-Co), consisting of sheets isolated by a thin ceramic insulator. Some concepts introduce flux barriers in the plane of the sheet and/or lamination thickness changes. The sheet lamination thickness should be less than 0.5 mm and the insulation less than 0.1mm.
2. Develop MM-AM processes and (adapted) hardware for high quality electrically conductive metals, magnetically conductive metals & ceramic insulators and their combinations, based on 3D micro-extrusion of powder filled paste and filaments with at least 80 wt% particle load, and subsequent densification by powder metallurgical processing. The aimed targets are: a. Electrically conductive material, preferably pure Cu with density > 95% and electrical conductivity of at least 80% IACS b. Soft magnetic material (e.g. electrical Fe-Si steel or Fe-Co) with density > 95%, magnetic permeability and losses as close as possible to conventional laminations of Fe-Si or Fe-Co.
c. Electrically/magnetically insulation ceramics (e.g. enamel porcelain) with thermal conductivity of at least 3W/mK and coefficient of thermal expansion that matches the one of the metals. The viscosity of the ceramic should allow plastic flow during sintering without infiltrating the densifying metal.
d. Good metal-ceramic adhesion, achieving the relevant dimensions and containing no cracks/flaws that jeopardize the strength or insulation properties (maximum allowed defect size of 0.10mm)
3. Develop a “tool” chain to obtain AM parts of electric machines with accurate geometry, and required electromagnetic functionality:
a. Making EM part design that is AM robust, based on understanding the potentials and limitations of MM-AM for EM: obtain accurate geometry via controlling the AM process (including shrinkage), and realizing the electromagnetic functionality (such as insulation between layers)
b. Studying the techno-economic feasibility of future EM concepts leveraging on AM incl. the potential for fully AM printed electrical machines and incl. a demonstration strip of MM-AM with all three materials together. To reach these challenging objectives, a multi-disciplinary project consortium is set up, including researchers and innovation managers from Ghent University, KU Leuven and VITO.