TiN/NbN nanoscale multilayer coatings deposited by High Power Impulse Magnetron Sputtering to protect medical grade CoCrMo alloys

ARUNACHALAM SUGUMARAN, Arunprabhu, PURANDARE, Yashodhan, SHUKLA, Krishnanand, KHAN, Imran, EHIASARIAN, Arutiun and HOVSEPIAN, Papken (2021). TiN/NbN nanoscale multilayer coatings deposited by High Power Impulse Magnetron Sputtering to protect medical grade CoCrMo alloys. Coatings, 11 (7).

Sugumaran-NanoscaleMultilayerCoatings(VoR).pdf - Published Version
Creative Commons Attribution.

Download (4MB) | Preview
Official URL: https://www.mdpi.com/2079-6412/11/7/867
Open Access URL: https://www.mdpi.com/2079-6412/11/7/867/pdf (Published version)
Link to published version:: https://doi.org/10.3390/coatings11070867


This study describes the performance of nanoscale multilayer TiN/NbN coatings deposited on CoCrMo medical-grade alloys by utilising novel mixed high power impulse magnetron sputtering (HIPIMS) and direct current unbalanced magnetron sputtering (UBM) technique in an industrial size vacuum coater. Scanning electron microscopy analysis showed that these coatings were extremely dense without any intercolumnar voids. The coating exhibited high hardness of 28 GPa, as well as low friction and wear coefficient of 0.7 and 1.4 × 10−14 m3·N−1·m−1, respectively, as compared to the bare material. Scratch tests revealed superior coating to substrate adhesion due to the HIPIMS etching prior to coating deposition. Energy-dispersive X-ray analysis of the wear debris generated during the impact test together with focused ion beam cross-section analysis in different locations of the impact crater revealed the coating failure mechanism and further confirmed the excellent coating to substrate bonding strength. Potentiodynamic polarisation tests in NaCl and Hank’s solutions revealed the clear passivation behaviour, several orders of magnitude lower corrosion currents, and high pitting potentials of the coating, which guarantee excellent protection to the base alloy in such aggressive environments. Inductively coupled plasma mass spectrometry analysis of Hank’s solution containing corrosion debris of the coated sample revealed that the leaching of harmful metal ions from the base material was reduced to below the detection limit of the technique, thus demonstrating the high barrier properties of the coating.

Item Type: Article
Uncontrolled Keywords: 0306 Physical Chemistry (incl. Structural); 0904 Chemical Engineering; 0912 Materials Engineering
Identification Number: https://doi.org/10.3390/coatings11070867
SWORD Depositor: Symplectic Elements
Depositing User: Symplectic Elements
Date Deposited: 16 Jul 2021 11:35
Last Modified: 23 Jul 2021 16:45
URI: https://shura.shu.ac.uk/id/eprint/28841

Actions (login required)

View Item View Item


Downloads per month over past year

View more statistics