Evaluation of Soft Magnetic Ferrosilicon FeSi 6.5 for Laser Beam Melting

The electromagnetic properties of soft magnetic materials are of decisive importance for the efficiency, running characteristics and performance of electric motors. To fulfil the target criteria as favorably as possible, high requirements are placed on the processing techniques of soft magnetic materials with regard to accuracy, reproducibility and quality. Through continuous improvements, novel additive manufacturing processes are also able to meet these requirements. They can already be a pragmatic alternative, where conventional processes reach their technological or economical limits. Laser beam melting of metals in a powder bed is one of the processes in which a workpiece is created from shapeless metal powder. Due to its generative character, new design elements can be utilized to build lightweight motors or to manufacture them economically in small quantities. However, the process does not allow the production of a laminated soft magnetic part, which leads to increased eddy current losses. To counteract these, a material with a high specific electrical resistance has to be used. This publication presents the selection of a material suitable for this application, taking into account the state of the art and the procedure for qualifying the material in the laser beam melting process. This enables potential users of additive manufacturing to estimate the effort for the qualification of a tailor-made alloy and to use it for their own applications.