Cleaner production of multi-scale surface textures using integrated ball-end and vibration-assisted milling

Surface texturing has emerged as a critical approach for enhancing the functional performance of engineered surfaces across various applications. However, existing methods often involve multi-step processes, excessive material waste, or the use of environmentally harmful chemicals. This study introduces a novel cleaner method for fabricating hierarchical multi-scale surface textures via integrated ball-end and vibration-assisted milling. The proposed technique synergistically combines millimeter-scale texturing through ball-end milling with micrometer-scale texturing via vibration assistance, enabling the creation of complex, multi-scale surface structures in a one-step process. A custom-designed 2-degree-of-freedom (2-DOF) flexible stage with a repeatability of +/- 0.1 mu m was developed to precisely control two-direction vibrations during milling. Comprehensive modeling and experimental validation were conducted across various machining conditions and surface configurations. The results demonstrate that the proposed method achieves a 50% reduction in energy consumption and a great decrease in material waste compared to traditional texturing processes. Surfaces machined with twodirection vibration assistance exhibited the highest degree of precision, with chip adhesion reduced from 8.98% to 0.49% compared to non-vibration conditions. Contact angle measurements revealed that finer textures promoted increased hydrophilicity, with contact angles decreasing from 86.5 degrees to 65.2 degrees as groove pitch reduced from 400 mu m to 200 mu m under two-direction vibration. This innovative approach offers significant advancements in sustainable manufacturing techniques for functional surfaces, providing a cleaner, more efficient alternative to conventional multi-step texturing methods.