Additive Manufactured and Topology Optimized Passive Shimming Elements for Permanent Magnetic Systems

TL;DR

This paper presents a cost-effective method combining topology optimization and additive manufacturing to create customized passive shimming elements that significantly improve magnetic field homogeneity in permanent magnet systems.

Contribution

It introduces a novel approach integrating topology optimization with 3D printing of soft magnetic materials for precise magnetic field correction.

Findings

Homogeneity increased by a factor of 35.

Good agreement between simulation and measurement.

Method applicable to cylindrical permanent magnets.

Abstract

A method to create a highly homogeneous magnetic field by applying topology optimized, additively manufactured shimming elements is investigated. The topology optimization algorithm can calculate a suitable permanent and nonlinear soft magnetic design that fulfills the desired field properties. The permanent magnetic particles are bonded in a polyamide matrix, and they are manufactured with a low-cost, end-user 3D printer. Stray field measurements and an inverse stray field simulation framework can determine printing and magnetization errors. The customized shimming elements are manufactured by a selective melting process which produces completely dense soft magnetic metal parts. The methodology is demonstrated on an example of two axial symmetric cylindrical magnets. In this case, the homogeneity can be increased by a factor of 35. Simulation and measurement results point out a good conformity.