Effect of Electroless NiP/PTFE Composite Coating on Mechanical Properties of AISI 420 SS and Its Corrosion Behaviour in Human Blood

Corrosion is one of the most common causes of failure of the medical instruments. Most of the medical instruments are made of martensitic stainless steel. As blood is highly corrosive, the instruments tend to corrode, when they come in contact with blood for a long period. Coating with a protective layer could be an alternative solution to avoid corrosion and increase the life of the instruments. In this work, we compared the corrosion resistance and mechanical properties of NiP and Ni–P-PTFE composite electroless coatings developed on martensitic stainless steel (grade AISI 420). The results show significant improvement in corrosion properties. Also, mechanical studies such as microhardness and nanohardness properties of the coatings has been performed. The addition of polytetrafluroethylene (PTFE) show higher corrosion resistivity but decreased mechanical properties.