Effect of Tribological and Electrochemical properties of AlTiN Coating for Medical Application

Physical Vapor Deposition technique is always an important technique to deposit metallic and ceramic coatings on different metallic substrates. The glow discharge process can be improved in a physical vapor deposition coating process by using least 2 lateral rotating cathodes with targets. Lateral Arc Rotating Cathode (LARC) technology was used to deposit AlTiN coating on stainless steel samples for biomedical implant application. The lateral rotation of cathode makes the uniform consumption of the cathodes in the coating chamber to get the maximum yield. The coating was characterized by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) for their uniformity and thickness. Open circuit potential (OCP), Electrochemical Impedance Spectroscopy (EIS) and Cyclic polarization test were performed for their corrosion behavior in ringer lactate solution. Tribological testing was also performed at three different load to evaluate the coefficient of friction of the coating. The Electrochemical tests indicated that corrosion resistance of the coated sample was better, than the uncoated substrate and it behaved like cathodically protected coating and showed more resistivity. The tribological test also showed improved coating quality with respect to the applied load.