A comparative analysis of functional performance in additively manufactured NiTi, Ti-6Al-4V, and 316L stainless steel architected metastructures.

Abstract

Additive Manufacturing (AM) offers unique capabilities for creating complex designs, such as architected structures, that are typically unattainable through conventional manufacturing methods. Recent advancements in 3D printing of shape memory alloys (SMAs) have enabled the design and development of smart structures capable of recovering their original shape after deformation. This innovation holds immense potential for applications such as biomedical implants and stents, where structures regain their original shape during loading and unloading cycles. This study investigates the functional performance of NiTi-based shape memory lattice structures in comparison to two commonly used commercial alloys: 316L stainless steel and Ti-6Al-4V titanium, both widely utilized in biomedical applications. For that, a lattice design with auxetic behavior and a negative Poisson's ratio was fabricated using the Laser Powder Bed Fusion (LPBF) technique. The samples underwent rigorous quality and performance evaluations, including microstructural analysis and cyclic compression testing to assess mechanical properties and energy dissipation capacity. The results reveal that NiTi samples exhibit distinct superelastic behavior and significantly higher energy dissipation under cyclic compression compared to 316L stainless steel and Ti-6Al-4V alloys. This study underscores the potential of NiTi-based architected metamaterials for achieving superior energy dissipation, positioning them as a promising solution for applications in the medical, aerospace, and automotive industries.