Gradient disorder in additively manufactured porous Ti–6Al–4V alloys enables isotropic energy absorption

This study systematically examines the mechanical behavior of Ti–6Al–4V porous lattices with gradient-disordered architectures fabricated by laser powder bed fusion (L-PBF). Finite-element simulations and quasi-static compression tests are combined to evaluate how controlled disorder—quantified by a regularity index (R = 0.2–0.8) affects stiffness, strength, energy absorption, and anisotropy. We find that moderate disorder, particularly R = 0.4 with a high proportion of disordered layers, provides the best balance between isotropy and overall mechanical performance. Disordered layers suppress shear-band formation, redistribute stress, and markedly enhance energy absorption—by up to an order of magnitude relative to ordered counterparts—while reducing anisotropy by > 70%; excessive disorder, however, compromises strength. The finite-element framework reliably captures deformation and failure initiation, although further refinement is needed to predict post-yield responses. Compared with conventional gradient designs, the trapezo-rhombic dodecahedron (TRD) configuration achieves significantly higher energy dissipation without sacrificing compressive strength. These findings provide practical guidelines for engineering lightweight, high-performance porous materials and highlight the utility of controlled disorder for biomedical and aerospace applications.