Mechanical Strain Tailoring via Magnetic Field Assisted 3D Printing of Iron Particles Embedded Polymer Nanocomposites

Abstract

Abstract The development of efficient, energy‐saving, and automated manufacturing of free‐form variable‐thickness polymer composite components has created a step‐change and enabled technology for the composites industry seeking geometry tailoring during a mould‐less and/or additive manufacturing such as that in 3D printing. The current article presents research on magnetic field assisted 3D printing of iron particles‐embedded thermoplastic polylactic acid, during a fused deposition method based 3D printing. The magnets are symmetrically fixed on both sides of the printed nanocomposite. The setup utilised Neodymium magnets with a constant strength below one Tesla. Observations have shown that the nanocomposites being printed undergo permanent macro‐scale deformations due to the extrinsic strains induced by the iron particles' magnetisation. To provide a theoretical understanding of the induced strains, a Multiphysics constitutive equation has been developed. The evolution of magnetisation within a relatively thick nanocomposite (5 mm thickness) has been studied. A correlation has been established between the extrinsic strains from the experimental data and the theoretical solution. The theory exhibits an accurate description of the field‐induced strains provided that real‐time temperatures for the printed layers are accounted for. The results demonstrate a viable and disruptive magnetic field‐equipped fabrication with ability for permanent geometry control during a process.

Keywords

• 3D printing
• composite manufacturing
• ferromagnetic particles
• magnetic polarization, 
• polymer nanocomposite