Fabrication of thermoplastic functionally gradient composite parts with anisotropic thermal conductive properties based on multicomponent fused deposition modeling 3D printing

A multicomponent fused deposition modeling 3D printing approach was proposed to fabricate thermoplastic functionally gradient composite parts (TFGCPs). The thermal conductive properties of the fabricated TFGCPs were studied by slice and as integrate, respectively. The variation of thermal conductivity by slice versus the number of layer shows that the curve of PCL/AlN has a constant slope, while the one of PCL/BN first increases and then decreases. It is attributed to that the network of thermal conduction is constructed when the loading of BN particles approaches 27wt%, leading to a substantial growth in thermal conductivity. The thermal conductivity of the TFGCPs as integrate lies between the one of pure PCL and homogeneous composite parts with AlN or BN fillers and has a relationship with the filler loading direction exhibiting thermal anisotropy. This study establishes the relationship between properties and structures of thermoplastic functionally gradient composite parts, which helps to lay a theoretical foundation of applications as intermediate layers.