Non-planar multiprocess additive manufacturing of multifunctional composites

Multiprocess additive manufacturing (AM) consists of integrating different 3D printing techniques to enable the fabrication of multifunctional parts, based on their geometry and material properties. The combination of fused filament fabrication (FFF) and direct ink writing (DIW) techniques, respectively involving thermoplastics and thermosetting polymers (or composites), often focuses on planar and small-scale applications (i.e., few cm), with limited nozzle orientation freedom for the fabrication of complex parts. Many industries, such as the aerospace sector, could benefit from the AM of lightweight multifunctional parts. For instance, one of the key aircraft components, the abradable seal coating, is applied on gas turbine engines casing to increase engine efficiency and is mechanically abraded by the rotor blades during engine startup. Abradable coatings made of thermosetting polymer could be 3D-printed using a multiprocess to obtain more functionalities. In this work, a non-planar multiprocess AM approach involving FFF of a complex large sandwich panel structure with low material density and large-scale DIW of an abradable thermosetting coating with controlled porosity for sound absorption potential, and better mechanical abradability than a commercial product, is presented. This multiprocess AM approach can be used to manufacture lightweight multifunctional structural parts for the automotive or aerospace industries.