Wear resistance of a nickel-based coating deposited by PTA on grey cast iron

The moulds for the production of glass bottles, made of cast iron, are subjected to very severe conditions of wear during use. Thus, it is essential to understand the wear mechanisms involved, in order to increase the equipment life. The present study intends to study the abrasion resistance of moulds submitted for long time at working conditions. The investigation was conducted on nickel-based coatings deposited by plasma transferred arc (PTA) on grey cast iron, using different arc currents. Micro-scale ball cratering abrasive wear test was used to evaluate the tribological properties of the as-deposited and heat treated coatings. The results show that micro-scale abrasion tests induce grooving and pitting wear mechanisms. Increasing the arc current decreased the hardness of the coatings and, consequently, their wear resistance. The hardness and wear resistance of the coatings was improved by increasing heat treatment holding time.