Experimental and Numerical Characterizations of <scp>PEEK</scp> Gyroid‐ <scp>BCC</scp> / <scp>FCC</scp> Lattices Fabricated by Material Extrusion Additive Manufacturing

ABSTRACT Polyether‐ether‐ketone (PEEK), a high‐performance engineering polymer, exhibits notable corrosion/high‐temperature resistance. Favorable rheological behaviors facilitate its applications in material extrusion additive manufacturing (MEAM) and are able to be formed into triply periodic minimal surfaces (TPMS) like gyroid for lightweight aerospace components. To enhance its mechanical properties and specific stiffness, novel hybrid lattice structures combining gyroid with face‐centered cubic (FCC) and body‐centered cubic (BCC) truss structures are designed via Boolean operations and fabricated by MEAM. Compression tests are performed to quantify the mechanical performances of MEAM‐prepared specimens. In addition, voxel‐mesh‐based finite element simulations analyze the quasi‐static structural behaviors of the hybrid lattice structures. Results demonstrate that both hybrid lattices exhibit superior mass‐normalized properties compared to the standard gyroid, where the gyroid‐FCC (GF) notably achieved 19.4% and 26.3% higher specific compressive strength and modulus, respectively. Furthermore, scanning electron microscopy characterization reveals that the additional truss that emerged in the hybrid lattice structures suppressed interlayer defects, thereby improving the damage tolerance of the hybrid lattice compared to the gyroid. Gyroid is significantly benefited from the addition of the truss, which provides a promising design paradigm for PEEK MEAM applications, potentially advancing the development of fabrication of lightweight components in aerospace and automotive industries.