Cobalt-based alloys have been widely used in implant components, especially in orthopaedic implants. The biocompatibility of CoCrMo alloy is related closely to this material’s excellent corrosion resistance, imparted by a thin passive chromium oxide layer with some minor contributions from Co and Mo oxides. The oxide film on CoCrMo alloy inhibits the dissolution of metal ions but is not always stable in the human body. There is a general agreement that corrosion is a serious problem for medical metallic materials. For joint replacements, they are exposed to tribological contacts and load so their performance (long-term durability) relies on both their corrosion and wear resistance. Diamond like carbon (DLC), with its extreme smoothness, hardness, low coefficient of friction, and biocompatibility is an excellent candidate to serve as a tribology-enhancing and corrosion-protective functional coating.

DLC-Coated CoCrMo Steel for Use in Medical Implants – Wear and Corrosion Resistance Influence of Different Surface Finishing Techniques

This paper reports on a method of synthesizing silicalite-1 molecular sieve-based anti-corrosive film on stainless steel surface. The corrosion resistance and mechanisms of four preparation methods were studied. The results show that the silicalite-1 anti-corrosive film prepared by silane hot pressing shows the best surface, crystallinity, and anti-corrosion performance. On this basis, the film formation and anti-corrosive mechanisms of silicalite-1 anti-corrosion film on stainless steel surfaces were analyzed.

Preparation of Silicalite-1 Molecular Sieve Composite Anticorrosive Film on Stainless Steel Surfaces and Its Anticorrosion Performance and Mechanism

In this work the corrosion resistance of PAPVD TiN hard coatings on AlSl 304 stainless steel with a titanium interlayer has been addressed. Cyclic voltammetry corrosion tests in NaCl 3.5% solutions were performed for samples prepared by depositing TiN/Ti onto steel using different deposition parameters. The surface morphology of the samples was examined by using a scanning electron microscope (SEM) and phase analysis was performed by X-ray diffraction (XRD). The cyclic voltammetry curves showed two distinct behaviours. Firstly, a reduction in corrosion resistance was observed when current density was increased for the whole potential range studied. The second observation, no less important, was the increase in corrosion resistance compared to the uncoated steel The TiN films deposited showing (111) preferred orientation showed better corrosion resistance than films presenting other orientations.

E. Tentardini

Papers

Corrosion Resistance of PAPVD TiN Coating on AISI 304 Stainless Steel