Wear and corrosion characteristics of nano-crystalline tantalum nitride coatings deposited on CoCrMo alloy for hip joint applications

• Published in: Materials characterization Vol. 182; p. 111516
• Main Authors: Corona-Gomez, J., Jack, T.A., Feng, R., Yang, Q.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-12-2021
• Subjects: Adhesion; Coatings; CoCrMo; Hardness; Hip joint implant; Tantalum nitride; Hip joint implant; Hardness; Coatings; CoCrMo; Tantalum nitride; Adhesion
• ISSN: 1044-5803; 1873-4189
• DOI: 10.1016/j.matchar.2021.111516

Osteolysis is the resorption or removal of bone tissue, which is associated with the accumulation of polyethylene particles and misalignment of hip joint implant components. The mechanical properties, adhesion, tribological, and corrosive properties of single-layered tantalum nitride (TaN) coatings on biomedical grade cobalt alloy were evaluated to determine the potential of these coatings to prevent osteolysis in hip joint replacement applications. The TaN coatings were deposited directly on biomedical grade CoCrMo alloy disks using a hybrid system of Plasma Enhanced Chemical Vapor Deposition (PECVD) and Physical Vapor Deposition (PVD) at different deposition temperatures. By increasing the deposition temperature from 350 °C to 500 °C, the mechanical properties and adhesion improved remarkably, without a significant change in the crystal structure according to XRD and XPS results. The ball-on-disk wear testing results showed that the wear rate of the polyethylene balls decreased by 5% when sliding against the TaN-500C sample compared to sliding against the uncoated alloy and was 23% lower than the TaN-350C sample. The electrochemical corrosion results indicated that the TaN coating deposited at 500 °C is about 15% more noble than the uncoated alloy, which allows the rapid formation of a protective passive layer. These results suggest that TaN is a promising coating for CoCrMo alloy to improve the lifetime of hip joint implants.
•TaN coatings with high hardness up to 28 GPa were fabricated.•TaN coatings exhibited high adhesion strength on biomedical CoCrMo alloy.•Tribological properties of TaN-500C is superior than CoCrMo alloy.•The TaN-500C sample is 15% more noble than CoCrMo alloy.