Enhancing the surface properties of additively manufactured NiTi alloys via post-processing treatments

Additive Manufacturing (AM) offers unprecedented advantages in producing complex, patient-specific implants, yet high surface roughness remains a major drawback. This research focuses on applying targeted chemical post-processing techniques to significantly refine the surface topography of Laser Powder Bed Fusion (LPBF) fabricated Nitinol (NiTi) alloys. By tailoring these post-treatments, the project aims to make 3D-printed shape memory alloys ideal for high-performance biomedical applications.

While 3D printing enables customized geometries for medical implants, the high "as-built" surface roughness inherent to LPBF components caused by partially melted powder particles can compromise functional performance and biocompatibility. Traditional mechanical polishing is often unfeasible for intricate lattice structures and internal geometries. By systematically investigating chemical and electropolishing methods, this research directly tackles these manufacturing challenges, optimizing surface topographies without compromising the underlying structural integrity of the alloy.

By optimizing surface treatments, we can bridge the gap between raw 3D-printed metals and the stringent surface standards required for next-generation biomedical implants and the aerospace industry.

Meriç Ikiz

PhD Researcher, School of Mechanical and Manufacturing Engineering, Dublin City University 

Initial results from this research have achieved an impressive 94% reduction in average surface roughness (Sa) and up to 90% reduction in peak-to-valley height (Sz) when comparing the as-built surface to post-electropolishing treatments. Moving forward, the project will apply further chemical combinations and evaluate the chemical behavior of the treated surfaces. These advancements pave the way for safer, more reliable, and tailor-made NiTi biomedical implants with enhanced biological and mechanical integration.

Equipment Used

• Surface Characterization & Metrology: Non-contact Optical Surface Profilometer, Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX)
• Sample Preparation & Processing: Mechanical Polishing and Grinding, Chemical/Electropolishing Post-Processing Setups

Biography

Meriç Ikiz is a PhD Researcher in the School of Mechanical and Manufacturing Engineering at Dublin City University (DCU), working under the supervision of Prof. Dermot Brabazon. Meriç’s research focuses on enhancing the surface properties of additively manufactured shape memory alloys (NiTi) by developing and optimizing advanced post-processing treatments for biomedical engineering applications. Before pursuing doctoral studies, Meriç gained valuable industrial experience in R&D and Quality Assurance at Oerlikon Metco Inc. (US) , specializing in materials engineering and process optimization.