Metal Release of Multilayer Coatings by Physical Vapour Deposition (PVD)

Abstract

Orthopaedic implants are mostly fabricated by Stainless Steel, Titanium, and Ni-Cr Alloys that consist of Chromium (Cr), Cobalt (Co), Nickel (Ni) and Molybdenum (Mo). 10-15% of population are affected by metals (Ni, Co, Cr, Mo) hypersensitivity reaction. Multilayer coating by Physical Vapour Deposition (PVD) has been applied onto orthopedic implants to prevent metallic ions leaching into human body. This paper aims to study the metal ions leaching of Cr, Ni, Mo, and Co from multilayer coatings of Chromium (Cr), Chromium Nitride (CrN), Chromium Carbonitride (CrCN) and Zirconium Nitride (ZrN) by Physical Vapour Deposition (PVD). Cr, CrN, CrCN and ZrN have been successfully deposited onto stainless steel substrates by CAPVD. 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). A seven days metal released test by ICP-MS showed that generally all ions concentration for Ni, Co, Mo decreased from uncoated substrate to multilayer coatings except for Cr. Metal released showed higher concentration for coatings deposition with longer deposition time at 10 minutes.