Influence of traverse speed on surface morphology of AISI 316L treated by Pulsating Water jet technology

Developing new techniques for surface modification of materials is crucial for enhancing the functionality of specific engineering components used across various fields. Sandblasting, acid etching, and laser surface treatments have known limitations in controlling surface roughness. This study addresses these gaps by investigating the surface texture generated on AISI 316L stainless steel using a Pulsating Water Jet (PWJ) technology. The research evaluates the effect of droplet density distribution by utilizing a traverse speed of v = 4–12 mm/s on surface topography, using linear and areal roughness metrics in accordance with ISO standards, alongside high-resolution SEM imaging of surface morphology. The findings demonstrate a distinct exponential decreasing trend in the roughness parameters, such as Ra = 28.29–1.74 μm; Rz = 214.23–11.11 μm; Sa P = 26.40–1.91 μm; Sz P = 307.60–18.96 μm; and Isotropy = 83.85–94.22 %, corresponding to an increase in traverse speed v = 4–12 mm/s. The lower speeds induce crater-rich, valley-dominated surfaces, while the higher speeds produce uniform, isotropic textures of a roughened surface. Wettability results on the generated surfaces showed a hydrophobic surface (>90°) at lower traverse speeds (v = 4 & 6 mm/s), which shifted to hydrophilic at higher traverse speeds (v = 8–12 mm/s). The findings demonstrate the viability of PWJ as a controllable surface treatment method for engineering applications and provide valuable insights into optimizing process–structure relationships through control of traverse speed.