Role of different density negative micro-pillars textured H13 surfaces on enhanced wettability and tribological performance

Abstract

The present study investigates how varying negative micro-pillar densities on H13 alloy, used in hot-forming dies, affect wettability with different fluids and tribological performance, alongside detailed morphological analysis. Recast materials, pockmarks, micro-voids, micro-cracks, and globules of debris are observed on EDM textured surfaces, and challenges are form accuracy and debris entrapment with higher textured density. The functional stressed surfaces, evident from XRD analysis, display hydrophobic properties with water and hydrophilic characteristics with mineral-oil-based emulsion. Increased texture density enhances these properties. Wettability properties transition of fabricated functional surfaces occurs within fluid surface energies of 48 to 72.8 mN/m. The coefficient of friction (COF) of the lower-density patterned surface is 20.42 % lower than the untextured surface, and the higher-density pattern shows a 13.48 % COF reduction compared to the lower-density surface. Key wear mechanisms include abrasion, adhesion, sharp edges and adhered debris deformation, and localized plastic deformation for untextured and textured surfaces.