Wettability Of Rough Surfaces Adhered By Solid Particle

Wetting phenomenon will be affected by chemical composition of solid materials,microstructure of surface and working condition.What is being widely concerned is that when there are particles on the solid,the interfacial wetting characteristics will be affected.In this paper,we made a thorough inquiry about the relevance of wettability between particles and smooth original surface and between particles and micro texture surface,also includes the effect law between three-dimensional topography parameters and the micro texture surfaces.We chose 45 steel and prepared 7 group different micro-texture surfaces including smooth original surface.We carried out the wetting experences on the 7 group surfaces by changing size,quality and number of particles and droplet volume.We measured different micro texture surfaces by non-contact 3D Optical Profiler Talysulf CCI Lite and characterized these surfaces by ISO25178.And we explored the wetting relevance between some three-dimensional topography parameters and micro-texture surfaces adhered by particles.In the paper,we can concluded that when the solid surface were adhered by particles,the interfacial contact angle had a certain amount of time dependence,which showed a changing trend that diminished quickly before becoming a stable condition.There was a changing trend about the solid-liquid equilibrium contact angle of the smooth original surface that would decrease with increasing of particle size,and decrease with increasing of particle quality,and increase with increasing of droplet volume.At the same time,we discovered capture phenomenon of the particles in the wetting process,which included the phenomenon of particle birdnesting and the phenomenon of particle adsorption.On the micro-texture surfaces,there was a wetting law that the contact angle would decrease before increasing with increasing of particle number,and increase with increasing of droplet volume.In addition,the wetting property of micro-texture surfaces adhered by particles were effected by shapes and directions of surface micro-pits,what’s more,there was a strong regularity between the wetting property of micro-texture surfaces adhered by particles and some three-dimensional topography parameters such as S_ku,S_sk,S_tr,S_al,S_dq,S_dr,S_da,S_dv and so on.