Processability & Microstructure of Fe-C System via L-PBF

Paper in proceeding, 2019

Although a variety of ferrous alloys exist in powder metallurgy, the number of approved ferrous alloys in additive manufacturing (AM), especially for structural applications, remains limited. This is in part due to the negative effect of carbon on processability during Laser Powder Bed Fusion (L-PBF). Where an increased carbon content promotes the formation of defects such as porosity and cracks. This work explores the AM processability of the Fe-C system at compositions ranging from pure iron to Fe-1.2wt.%C. Microstructural analysis was conducted to determine the fraction, location and distribution of formed defects. Allowing for the development of a process window that could define defect formation mechanisms, along with the influence of carbon content on said mechanisms. Using this window a robust L-PBF process for the manufacturing of defect-free Fe-C components could be established. As well as a basis for further powder and process development of ferrous alloys for structural applications.