Laser beam melting of functionally graded materials with application-adapted tailoring of magnetic and mechanical performance

Abstract

The processing of functionally graded materials (FGMs) using laser beam melting (LBM) is a promising technique for increasing the efficiency of conventional machine components, especially for e-mobility. Therefore, the aim of the current study is to prove the manufacturability of tailored mechanical and magnetic properties in a rotor for an electric motor. For this purpose, the design of additively manufactured rotors with application-adapted tailoring of the properties in the same component using FGM was proposed. The first step was to investigate whether the FGM of the components, i.e. soft-magnetic steel for the rotor core and high-strength steel for the rotor shaft ends, are suitable for machining by LBM. Subsequently, multi-material samples of the two investigated steel types with their different arrangement were processed by LBM. Furthermore, post-processing heat treatments and their effects on the microstructure and resulting magnetic properties as well as the mechanical performance of mono- and multi-material samples were analyzed. The combination of LBM and an additional post heat treatment enables both the formation of a good adhesive bond between the two alloys and the desired tailoring of the properties in the FGMs investigated.