B L O G
XINDA MOTOR
  1. Home
  2. Knowhow

Can the motor core also be 3D printed? New Developments in Research on Magnetic Cores for Motors

Date:2023-07-12   Author:XINDA MOTOR

The magnetic core is a sheet of magnetic material with high magnetic permeability. They are commonly used for field guidance in a variety of electrical systems and machines, including electromagnets, transformers, motors, generators, inductors and other magnetic components.


So far, the 3D printing of magnetic cores has been a challenge due to the difficulty of maintaining the efficiency of the magnetic core. But a research team has now proposed a comprehensive laser-based additive manufacturing workflow that they say can produce products with superior magnetic properties to soft magnetic composites.




....

© 3D Science Valley White Paper

image
3D printing electromagnetic materials

Additive manufacturing of metals with electromagnetic properties is an emerging field of research. Some motor R&D teams are developing and integrating their own 3D printed components and incorporating them into systems, where freedom of design is one of the keys to innovation.

For example, 3D printing functionally complex parts with magnetic and electrical properties could pave the way for custom embedded motors, actuators, circuits and gearboxes. Such machines can be produced in digital manufacturing facilities, requiring less assembly, post-processing, etc., since many parts are 3D printed. But due to various reasons, the vision of 3D printing large and complex motor parts has not been realized. Mainly because there are certain challenging requirements to be met on the device side, such as small air gaps for increased power density, not to mention issues with multi-material components. So far, research has focused on more "basic" components, such as 3D printed soft-magnetic rotors, copper coils and alumina heat spreaders. Of course, the soft magnetic core is also one of the key points, but the most important obstacle to be solved in the 3D printing process is how to minimize the loss of the magnetic core.


 Tallinn University of Technology

The picture above shows a set of 3D printed sample cubes, showing the effect of laser power and printing speed on the magnetic core structure.

image

Optimized 3D printing workflow


To demonstrate the optimized 3D printed magnetic core workflow, the researchers determined the optimal process parameters for the application, including laser power, scanning speed, hatch spacing and layer thickness. And the effect of annealing parameters is obtained through research to achieve the minimum DC loss, quasi-static, hysteresis loss and the highest magnetic permeability. The best annealing temperature is determined to be 1200°C, the highest relative density is 99.86%, the lowest surface roughness is 0.041mm, the minimum hysteresis loss is 0.8W/kg, and the ultimate yield strength is 420MPa.


 Influence of energy input on surface roughness of 3D printed magnetic core

Ultimately, the researchers confirmed that laser-based metal additive manufacturing is a viable method for 3D printing motor core materials. In future research work, the researchers intend to characterize the microstructure of the part to understand grain size and grain orientation, and their effect on magnetic permeability and strength. The researchers will also further investigate ways to optimize the geometry of the core for 3D printing to improve performance.