Growth and characterization of tantalum multilayer thin films on CoCrMo alloy for orthopedic implant applications

Publication date: 1 January 2018
Source:Thin Solid Films, Volume 645
Author(s): Sheida Shiri, Chunzi Zhang, Akindele Odeshi, Qiaoqin Yang
In this study, tantalum (Ta) thin films deposited (by magnetron sputtering) on CoCrMo alloy substrates were studied using X-Ray Diffraction, Scanning Electron Microscopy and Rockwell C indentation tests. The results show that α-Ta single phase thin films, the desired phase for orthopedic implant applications, with low adhesion forms at substrate temperature of 400°C or above while a mixture of α-Ta and β-Ta forms at substrate temperature lower than 400°C. A negative bias of 78V applied to substrate results in development of adherent β-Ta thin film at room temperature. Based on the results, a multilayered gradient Ta thin film, β-Ta/β-Ta+α-Ta/α-Ta, with controlled structure has been developed on biomedical CoCrMo alloy sheets. The film shows high adhesion, which is promising for biomedical applications.