Tribocorrosion Mechanisms of Inconel^® 718 Under Intermittent Sliding in Alkaline Environment

Inconel 718 (IN718) is a nickel-based superalloy known for its outstanding resistance to both wear and corrosion, making it widely used in numerous industrial sectors. The primary objective of this study was to perform a comparative evaluation of the tribocorrosion behavior of conventionally manufactured and additively manufactured Inconel 718 alloys in an alkaline environment, both in the as-manufactured and heat-treated conditions. Tribocorrosion tests were conducted using a ball-on-plate tribological stand. During the experiments, both the coefficient of friction and electrochemical current were continuously monitored, while the resulting wear was evaluated both quantitatively and qualitatively. Under tribocorrosion conditions, lower material loss was observed for the additively manufactured samples. The volumetric wear of the additively manufactured alloy decreased from 0.888 × 10^-3 mm³ in the manufactured condition to 0.719 × 10^-3 mm³ after heat treatment, whereas for the conventionally manufactured alloy the wear volume decreased from 0.906 × 10^-3 mm³ to 0.772 × 10^-3 mm³ after heat treatment. The results indicate that heat treatment reduced material loss under tribocorrosion conditions for both manufacturing methods (about 15-19%). The presented analysis also showed that the manufacturing method did not affect the volumetric wear under tribocorrosion conditions.