Towards mass production of graphene-reinforced inconel 718 by powder injection moulding

Abstract

Powder Injection Moulding (PIM) offers a promising avenue for economically producing intricate, graphene-reinforced superalloy parts with complex geometries, overcoming current limitations in their industrialization for engineering applications. The organic binder used in PIM has the potential to be the graphene dispersion media in the superalloy powder saving the need for other processes. However, this addition method needs to be comprehensively evaluated due to the inherent challenges within the PIM process. This study pioneers the utilization of PIM to fabricate Inconel 718 superalloy, incorporating varying levels of reduced graphene oxide (rGO). The effective dispersion of rGO during mixing and its prevalence after debinding and sintering stages have been demonstrated by combining several characterization methods. Graphenic species are identified in all the process stages, though in the sintered microstructure these are commonly accompanied by niobium carbides, which indicates that rGO is partly degraded during the PIM process by reacting with the matrix elements. The encouraging results of this work establish the grounds to produce graphene-reinforced superalloys by PIM and call for further investigation, which can be extended to other metal alloys and ceramics.