Hierarchical Surface Textures for Improved Coating Durability Using Double-Sided Incremental Forming

Abstract

This study investigates the impact of surface texturing on the durability of slippery liquid-infused porous surface (SLIPS) coatings applied to sheet metal substrates by the double-sided incremental forming (DSIF) process. Toolmarks generated during the DSIF process were leveraged as an efficient method for texturing, enabling both the formation and texturing of surfaces using a single set of universal tools. The effects of texture patterns, spacing, and tool movement on the SLIPS performance were evaluated by comparing samples generated in the presence and absence of tool spinning/rotation. The results indicate that textures with dimple patterns significantly improve coating durability by acting as lubricant reservoirs, reducing oil depletion, and supporting self-healing. In contrast, continuous grooves were less effective due to limited capillary action and increased edge effects. Tool spinning further enhanced the surface topography, producing an undulating texture that minimized contact line pinning and improved the surface hydrophobicity. Low-speed spinning (approximately 10 rpm) facilitated a transition to mixed sliding–rolling friction, resulting in smoother textures and extended coating durability. Combining dimple patterns and controlled spinning provides a synergistic approach for optimizing SLIPS coatings, offering a practical solution for enhancing durability without requiring additional equipment. This study underscores the potential of controlled texturing and tool movement to improve the SLIPS efficacy and broaden its applications in industrial, clinical, and consumer environments.