Effect of Surface Finishing and Nitriding on the Wetting Properties of Hot Forging Tools

Lubrication is a critical aspect of the metal forming process and it is strongly influenced by the surface texture of the tool-forming surfaces. This study is focused on determining the effect of surface finish and heat treatment on wettability involving commonly used lubrication agents. Three different finishing states are evaluated (as-ground, as-polished and as-nitrided). Surface topography was measured using a focus variation microscope. Parametric evaluation was carried out according to ISO 25178, including fractal methods. The functional relations between the finish state and wettability, lubricating agent and wettability, selected surface parameters and wettability, as well as between finish state and selected surface parameters, were designated. The results showed that surface finishing treatments, particularly nitriding, influenced both surface roughness and wettability, with varying effects observed across different lubricants and droplet sizes. The findings provide valuable insights into the optimization of lubrication strategies for metal forming processes, highlighting the importance of tailored surface treatments for enhanced tool performance and longevity.