The urgent need for sustainable resource management and reduction of greenhouse gas emissions has caused a paradigm shift towards circular economy principles across various industries. While recycling routes for economically dominating alloys like steel have been well-established, the transition to sustainable metallurgy now extends to niche materials such as NiTi shape memory alloys (SMAs) as well. The production of pure Nickel and Titanium entails substantial energy consumption and emits significant CO₂ volumes. Moreover, the manufacturing processes of NiTi products, such as stents, often lead to considerable material losses due to techniques like gun drilling and laser cutting.

The present study investigates sustainability aspects of NiTi SMAs, focusing on the challenges of impurities, which detrimentally affect transformation temperatures and fatigue lives during recycling. We explore the feasibility of NiTi recycling through different remelting strategies, employing a theoretical model to analyze the influence of geometry, surface conditions, and processing parameters on the chemical purity and phase transformation behavior of recycled NiTi SMAs. Our approach involves laboratory-scale recycling experiments based on arc melting.

Additionally, we delve into possible second-life applications for NiTi SMAs, considering scenarios where recycling processes may result in significant alterations to functional properties. Our research efforts aim to contribute to the development of sustainable metallurgical practices for NiTi SMA manufacturing.