Mechanical Properties of Cr/CrN/CrCN/ZrN Multilayer Coatings by Physical Vapour Deposition (PVD)

Multilayer coating onto orthopedic implants has been studied extensively due to their excellence mechanical and biological properties. A multilayer coating was coated onto metal implants to prevent the leaching of metallic ions into human body. This paper aims to study the hardness of multilayer coatings of Chromium (Cr), Chromium Nitride (CrN), Chromium Carbonitride (CrCN) and Zirconium Nitride (ZrN) by Physical Vapour Deposition (PVD). The deposited multilayer coating was characterised by Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) and Energy Dispersive X-ray (EDX). Cr, CrN, CrCN and ZrN have been successfully deposited onto stainless steel substrates by PVD. XRD analysis detected major peak in preferred orientation of (200) and other peaks with (111), (220), (311) for CrN cubic phase. For CrCN, XRD analysis detected only low intensity peaks of Cr7C3 and ZrN peaks with preferred orientation of (111), (200) with other peak (220), (311) and (222). Microvickers Hardness results showed an increment in hardness value from substrates with 160HV to 174HV for Cr, 236HV for CrN, 362HV for CrCN, 364HV for ZrN and 370HV for multilayer coatings.