Evaluation of Gamma irradiated Ti6Al4V and Silver alloyed a-C coatings as friction pair via Response Surface Methodology

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ABSTRACT

The present study discusses a possible friction pair of silver alloyed a-C-coated stainless steel 316 LVM and gamma-irradiated Ti6Al4V alloy for application in medical implants. The morphology and structure of the materials were studied using AFM and XRD analysis respectively. The experiments for the dry-simulated tribotest were designed using Box-Behnken design (BBD)- based L₁₅ array. ANOVA analysis was performed to evaluate the influence of design parameters (applied load in N, sliding velocity in m/s and sliding distance in m) on the response variables (surface quality, friction coefficient, mass loss in the coating and Vickers microhardness). The optimum wear parameters obtained using BBD was 5.75 N, 0.1 m/s and 1515 m. What is more, the worn surface analysis of the gamma-irradiated Ti6Al4V indicated grooving and scuffing as primary wear mechanism whereas the coated surface witnessed mild abrasion. The XRD pattern propounded the formation of TiO₂ oxide layer on the surface of the pin. Raman studies on the worn silver alloyed a-C-coated surface indicate no statistically significant loss in the structural make-up of the coating. During sliding, the silver-alloyed a-C- coated surface and gamma-irradiated Ti6Al4V counterbody suffered three-body wear mechanism.

KEYWORDS:

• Silver alloyed a-C coating
• gamma irradiation
• biomedical
• tribology
• Box-Behnken design

Acknowledgements

The authors would like to thank TEQIP III, National Institute of Technology Silchar, Assam, India for partially funding the work. The authors would like to acknowledge Central Instrument Facility, Indian Institute of Technology Guwahati (Assam, India), Central Research Facility, Indian Institute of Technology Kharagpur (West Bengal, India), Department of Mechanical Engineering, Adhi College of Engineering & Technology, Chennai (Tamil Nadu, India), Centre of Nanoscience & Nanotechnology, Sathyabama University, Chennai (Tamil Nadu, India) and Ingenious Tools & Design Solution, Ghaziabad (Uttar Pradesh, India) for providing the necessary infrastructure to carry out the experimental work.

Disclosure Statement

No potential conflict of interest was reported by the author(s).