Metallic 3D printing technology for magnetically active components of electric machines
Realization period:01.07. 2022 – 30.06. 2025
Leader at TUL:Ing. Jiří Šafka, Ph.D.
Today's industrial sphere is characterized by the introduction of progressive innovations, utterly new production technologies, and, above all, a massive degree of optimization, be it functional, technological, economic, or other. Materials research is no exception. There is a constant development in the field of magnetically soft materials. Every year, manufacturers introduce new materials with better properties. It is mainly about reducing losses and increasing permeability. The achieved parameters depend on non-controllable physical properties, e.g., quantum properties of atoms, interatomic forces determining the mutual bonds of particles. And also on parameters influenced by the composition and processing technologies, such as the metallographic structure of matter.
For magnetically soft materials, both alloys and conventional technologies for producing a non-oriented and magnetically oriented strip with an oriented metallographic plane structure (GOSS) and its modification by laser trimming of magnetic domains are being developed. The use of amorphous metal glasses and nanocrystalline materials achieving high permeability values, very low coercive force, and low electrical conductivity is gaining momentum. As a result, they excel at small losses. Recently, a growing trend of composite materials with a plastic matrix processed by extrusion or injection molding technology is also known. Last but not least, it is the processing by additive technologies that this project focuses on.
Selective laser melting (SLM) technology excels in creating complex metal parts with an internally defined structure, which are difficult to produce by conventional methods. In each model layer, the metal powder with the prescribed grain size is spread in the building space and melted using a powerful laser, thus merging the current and previous printed layers and gradually creating the overall model. The great advantage of this technology is that it allows the creation of any complex structures. This technology generates minimal waste (only in similarly necessary support structures). SLM technology is therefore advantageous for processing expensive materials and also minimizes the environmental impact of production.
The high-temperature gradients created by laser melting affect the structure of the resulting material. It brings in internal stresses and increases the energy needed to move the domain walls. The result is a deterioration of the magnetic properties. Subsequent heat treatment plays an important role here - annealing, which minimizes this internal stress.
The presented project aims to map the use of 3D printing technology of magnetically active components of electric motors and actuators. The basis is the research of the impact of technological parameters of 3D printing in SLM technology on the magnetic properties of the material processed.
Subsequently, the electric motor will be optimized to maximize profit and suppress the undesirable properties of parts produced by SLM technology. The altered properties of the active material of the motor require modifications of the engine design to achieve optimal efficiency, minimize weight, and economic efficiency of production.
The research results will be verified by the production of functional samples and their comparison with conventional motors. The control algorithm of the frequency converter used to power the new engine will be optimized in the project's final phase to increase the drive efficiency and dynamics, considering the differences between motors manufactured with conventional technology.
The presented research project systematically covers the entire production process from the material used, the technology of production of magnetic components, the construction of the motor to its control.