Investigation of micro pit array on titanium alloy with hydrophobic surface by through-mask electrochemical micromachining

Abstract In order to obtain higher contact angles and improve the hydrophobicity of titanium alloy, the micro pit arrays were fabricated by the through-mask electrochemical micromachining (TMEMM). The theoretical model of surface hydrophobicity between the contact angle and the geometry size of micro pit arrays was developed. Moreover, the multi physical field coupling simulation of TMEMM was carried out. Thus, the direct mapping relationship between the contact angle and the process parameters was obtained by combining the theoretical model with the simulation results. The effect of process prameters, such as electrolyte mass fraction, mask size and processing voltage, was investigated. The optimal combination of process parameters was predicted and verified by experiments. The results show that the errors of the measured values of diameter, spacing, depth and surface contact angle of the micro pit arrays are 2.49%, 6.87%, 7.40% and 6.01% respectively, which indicates that the hydrophobic textured surface with a contact angle of about 141° is successfully fabricated without the modification of low surface energy materials.