Importance of surface roughness to the performance of additively-manufactured magnets

Advances in additive manufacturing (AM) have established it as a transformative manufacturing technique for fabricating magnets. This enables the fabrication of complex geometries and functionally graded structures that are difficult to achieve using conventional methods. However, a key limitation to the direct industrial adoption of 3D-printed magnets is achieving precise dimensional accuracy and consistent magnetic characteristics. These are essential for the functional integrity and reliable performance of magnetic assemblies used across a wide range of applications. This paper reviews the importance of dimensional accuracy and surface roughness in 3D-printed magnets and their direct influence on magnetic functionality. It also provides a comprehensive overview of common fabrication techniques for permanent magnets, including conventional processing and AM, highlighting their respective capabilities and limitations. In addition, the study examines the effect of surface roughness and geometric deviations on magnetic performance. It also discusses advanced metrological evaluation techniques and tools for assessing dimensional accuracy, surface topography, and other dimensional characteristics of printed magnets. The review concludes by outlining a way forward, focusing on predictive modelling, hybrid manufacturing techniques, and eco-efficient post-processing frameworks to bridge the gap between precision manufacturing and scalable production of high-performance 3D-printed magnets.