Effect of process parameters on the texture evolution of Fe-6.5 wt% Si soft magnetic alloys manufactured via laser powder bed fusion

Abstract

Numerous attempts have been made to manufacture high-Si steels using a laser powder bed fusion process. It has been established that controlling texture is critical to enhancing their magnetic properties. In this study, a comprehensive analysis was conducted to ascertain the texture evolution in Fe-Si alloys under various laser powers (P) and scanning speeds (V). The analysis revealed that texture formation in the fusion process is primarily influenced by two factors: $P/V$, the line energy density, and $P/\sqrt{V}$, associated with enthalpy. Both the melt-pool sizes and the threshold value for the transition in melting mode were effectively characterized by the $P/\sqrt{V}$ term, while the $P/V$ term proved essential for texture development under the same melting mode. In keyhole mode, an increase in $P/V$ led to a transition from the {001}<100> to the {111}<1−10> texture. In conduction mode, an increase in $P/V$ led to a transition from the {001}<100> to the {001}<110> texture, along with the development of a strong θ-fiber texture at intermediate $P/V$ values. Furthermore, by examining the mechanisms behind the development of these textures, potential conditions for the development of a strong Goss texture were identified. Finally, significant improvements in magnetic properties were achieved through texture optimization.