Fabrication of hydrophobic Ti3SiC2 surface with micro-grooved structures by wire electrical discharge machining

The near-superhydrophobic Ti3SiC2 surfaces with regular and controllable micro-grooved structures were fabricated by wire electrical discharge machining (WEDM). The surface topographies and chemical compositions of smooth and micro-grooved Ti3SiC2 surfaces were characterized. The micro removal mechanism of Ti3SiC2 in the process of electrical discharge machining was also analyzed. The wetting mechanism of micro-grooved Ti3SiC2 surface was discussed along with the static contact angle, anisotropic wettability and contact angle evolution versus time. The relationships between parallel and perpendicular contact angles, depth-width ratio of micro grooved structures and surface roughness of textured surface were investigated. The experimental results show that the parallel contact angle on the textured Ti3SiC2 surface increased by about 164% compared with the one on the smooth surface, and near-superhydrophobic surface with obvious anisotropy was roughly achieved. The experimental parallel contact angles were very close to theoretical contact angles calculated by Cassie-Baxter formula. It is confirmed that the depth-width ratio may be used to predict the parallel contact angle with the average prediction error of 2.4%. The perpendicular contact angles had a good correlation with the depth-width ratio and surface roughness.