Reducing anisotropy of a part fabricated by material extrusion via warm isostatic pressure (WIP) process

With the development of material extrusion (ME) technology, ME parts have been widely adopted in various industries owing to their cost-effectiveness. However, air gaps, which are intrinsic problems in the process, are the main reason for the low coalescence, resulting in deteriorating mechanical properties. In addition, the presence of an air gap increases the deviation of the mechanical properties in a build-orientation and worsens the difference in mechanical properties with build orientations. Thus, the reduction of air gaps should be achieved to expand the applications of ME parts. In this study, the authors investigated the effectiveness of a warm isostatic pressure (WIP) process to reduce the air gap. It can be concluded that the WIP process can be helpful to reduce anisotropy and to improve the ductility and bonding force between layers. • Improving bonding force between layers through WIP process. • Effective increase of ultimate tensile strength and toughness. • Change the fracture behavior of FDM parts from brittle to ductile. • Effectively reduce the anisotropy of the FDM part. • Increasing coalescence of FDM parts through effective air gap reduction.