Abstract: In biological materials, micro-flow devices, self-cleaning materials, food pharmacy or other fields, working surface of the parts needs to have specific wettability in order to satisfy the service performance. Surface micro-topography has very important influence on surface wettability. Surface micro-topography is evaluated by many aspects of parameters. Workpieces of 1Cr18Ni9Ti is machined by electrochemical method, the different surface topography is obtained by regulating the processing parameters. Ra, Rz and Ry are used to reflect the contour height features, S and Sm are used to reflect contour width features, and Sm/Ra, Sm/Ry and Sm/Rz are used to reflect the shape features of the contour. Surface wettability with different surface topography is obtained by experiment and the results show that the bigger the parameter of Ra, the smaller the parameter of Sm, the smaller the parameter of Sm/Ra, Sm/Ry and Sm/Rz, the better the surface wettability. Regression analysis and BP neural network are used to simulate and predict the surface contact angle, the results show that the preliminary design of micro-topography based on regression analysis and the prediction of the influence of micro-topography parameter on the contact angle is feasible.

Key words: Electrochemical machining, Surface micro-topography, Surface wettability