Carbon fibre-reinforced plastic (CFRP) composites, prized for their exceptional properties, often encounter surface quality issues during slotting due to their inherent heterogeneity. This paper tackles CFRP slotting challenges by employing multi-tooth mills in experiments with various fibre orientations and tool feed rates. In-plane scratching tests are performed under linearly varying loads; then, slotting experiments are conducted at different parameters. The scratching test results indicate that the fibre orientation and cutting angles have significant influences on forces and fracture process. The slotting experiments demonstrate that cutting forces and surface roughness S_a of the bottom slotting surface are notably affected by the fibre orientation, with disparities between up-milling and down-milling sides. Reorganising S_a data by local fibre cutting angle θ highlights consistent S_a variations between up-milling and down-milling sides for 0° ≤ θ ≤ 90°, with lower S_a on the up-milling side. However, for 90° < θ ≤ 150°, S_a variations diverge, with lower S_a on the down-milling side. Unexpectedly, S_a on the down-milling side decreases with increasing θ in this range. Additionally, the tool feed rate exerts a more pronounced influence on S_a on the up-milling side.

Aluminum (Al) is a metal material commonly used in industry, but its surface is easily corroded. The superhydrophobic surface has great self-cleaning and anti-corrosion properties, and it is an ideal method to construct a functional aluminum surface. Here, a simple method based on cyclic chemical etching was proposed to achieve the superhydrophobic Al surface with honeycomb structures. The surface of the sample etched eight times comprised micro/nano-scale honeycomb cavities, while exhibiting a water contact angle (WCA) of 135°. After being treated with an octadecanethiol (C₁₈H₃₈S) methanol solution, this sample demonstrated a WCA of 153.1°. A self-cleaning test was performed on the superhydrophobic Al surface, showing the excellent self-cleaning property. Finally, the electrochemical anti-corrosion test demonstrated that the above-mentioned superhydrophobic Al surface had great corrosion resistance property. Overall, this work has enriched the theory and technology for fabricating aluminum to achieve superhydrophobic.