Compressive response of additively manufactured Ti–6Al–4V Triply Periodic Minimal Surface structures with different unit cell designs for biomedical implant applications

Abstract

Cellular structures such as Triply Periodic Minimal Surface (TPMS) lattices demonstrate mechanical properties that closely mimic those of human bone tissue. The advent of advanced additive manufacturing technologies has catalysed interest in the application of TPMS lattices in bio-implant scenarios addressing the need for lightweight structures that exhibit similar mechanical properties as that of human bone. Though much more extensive works were carried out on traditional strut-based lattice configurations, but to address current scenario of industrial requirements, need to focus more on sheet based TPMS lattices. Considering the importance of additively manufactured TPMS lattices for implant applications, it is necessary to study the Compressive mechanical properties and anisotropic behaviour in detail and its suitability for bone implant applications. Therefore, the current study focusses on investigating both unit cell and full-scale models (FSM) of different TPMS lattices, specifically focusing on their elastic and plastic properties, anisotropic behaviour, and deformation characteristics across varying relative densities using numerical methods. The predicted mechanical properties are experimentally validated through compression tests conducted on several additively manufactured Ti-6Al-4V TPMS lattices. Research findings reveal that the elastic properties of these structures follow a power-law relationship with relative density, consistent with the established scaling laws for cellular materials. Analysis based on scaling laws demonstrated that under shear and hydrostatic loading conditions, all lattice types exhibited stretching-dominated behaviour. Overall, the mechanical properties predicted through the numerical methods were in substantial agreement with experimental data, although notable deviations in the elastic properties were attributed to inconsistencies in the additive manufacturing process, with minimal deviations observed in the plastic properties. It is expected that the research findings will make a valuable contribution to the field of biomedical materials, providing insights that could enlighten the development of next-generation lattice structures for load-bearing and bone implant applications. © 2025 Elsevier Ltd