Research On Design Andanti-frost Performance Ofhydrophobicmicrostructures Based On Metalmaterial

Inspired by super hydrophobic phenomena in nature,a trench and square cylinder model with two kinds of wettability in this paper is designed on the surfaces of aluminum alloy and brass,The structures on both the aluminum alloy and brass are realized by the high speed wire electrical discharge machining(HS-WEDM).The size,morphology,wettability and wetting mechanism of the samples were observed and analyzed.And the frost-resistance test has been made on the different wetting surface.It is found that the shape and size of groove and square cylindrical composite microstructures can be realized on the surface of aluminum alloy and brass.The wetting mechanism shows that the contact state of the water droplets on the machined surface is the result of the interaction of the sub millimeter trench / square column and the micron or nano scale composite structure on the surface.The stability test results show that the micro-structures had good mechanical stability and were not easy to lose surface wettability.In the constant temperature and humidity conditions,the wettability of the sample surface was stable.But once the outside temperature and humidity changed,The contact state of water droplets on the specimen surface would change.The frost-resistance test results show that the wettability of materials surface was the main factor to the effect of anti-frost.Due to the micro structures of the substrate surface would increase the apparent contact angle and decreasethe solid-liquid contact area,thus delaying the undercooling increases speed,the surface micro structure has certain effect of anti-frost.