Titanium Nitride Coatings on Ti Alloys by PIRAC for Orthopedic Implants

Abstract:

In the present work, Ti and Ti-6Al-4V were PIRAC nitrided at the relatively low temperatures of 700-850°C. To obtain thicker TiN layers, 3 stage PIRAC based coating was applied: (1) PIRAC nitriding followed by (2) PIRAC titanizing followed by (3) additional PIRAC nitriding. The microstructure and phase composition of the obtained surface layers were characterized employing X-ray diffraction and scanning electron microscopy with chemical analysis (SEM/EDS). Bending test was employed to evaluate the coatings adhesion to the substrate. Lower PIRAC nitriding temperatures yielded smoother TiN coatings with a more gradual microhardness decrease from the surface to the bulk. All PIRAC TiN based coatings have excellent adhesion to substrate – no delamination of the coating in bending tests was observed. The best combination of microhardness and adhesion was obtained using 3 stage PIRAC process.

• Periodical: Key Engineering Materials (Volumes 434-435)
• Pages: 481-484
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.434-435.481
• Online since: March 2010
• Authors: Shou Jun Wu, Elazar Y. Gutmanas, I. Gotman
• Keywords: Adhesion, Microstructure Characterization, PIRAC, Titanium Nitride Coating, Titanizing

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