Gradient structural disorder induces isotropic and high-energy-absorbing behavior in porous Ti-6Al-4V Alloy

Abstract

Porous Ti-6Al-4V alloys, renowned for their lightweight nature and exceptional energy-absorption capabilities, hold great promise for aerospace and biomedical applications. However, their widespread adoption has been limited by challenges such as mechanical anisotropy and localized stress concentrations. In this study, we propose novel gradient-disordered porous architectures fabricated via advanced laser powder bed fusion (L-PBF) to overcome these issues. Trapezo-rhombic dodecahedron cells were employed as the basic structural unit, and gradient-disordered layers (1–4) were strategically integrated to improve mechanical performance through controlled heterogeneity. Experimental results revealed that the gradient-disordered designs significantly enhanced energy absorption, achieving increases of up to 600% along the y-axis and 300% along the x-axis compared with ordered structures. Furthermore, these architectures reduced anisotropy in normalized Young’s modulus and energy absorption by 96% and 93%, respectively, resulting in nearly isotropic behavior. Compression tests and finite element simulations confirmed improved isotropy, suppression of shear band development, and more uniform stress distribution, underscoring the robustness of the proposed designs. Overall, these findings highlight gradient-disordered porous architectures as a promising strategy for optimizing porous Ti-6Al-4V alloys, particularly in aerospace and biomedical applications requiring high energy absorption, isotropy, and durability.