附着固体颗粒的粗糙表面润湿特性研究

发布时间：2019-06-08 10:39

【摘要】：润湿现象会受到固体材料化学组成、表面微观结构和工况条件等的影响。当固体表面附着颗粒时对其界面润湿特性产生的作用效应受到了学者们的广泛关注。本文主要探究了颗粒与光滑原始表面和微织构表面润湿特性的关联性以及三维形貌参数对附着颗粒的微织构表面润湿性能的影响规律。本文选用45钢并通过激光打标技术制备出了包括光滑原始表面在内的7组具有不同微观结构的表面,通过改变附着表面颗粒的粒度、质量、颗粒数目、液滴体积等在7组表面上进行润湿试验,分别探究了颗粒对光滑原始表面和微织构表面润湿特性的影响规律。采用Talysulf CCI Lite非接触式三维光学轮廓仪对不同微织构表面进行了测量,并选用了适宜的ISO25178系列三维形貌表征参数进行了表征,并且探究了部分三维形貌参数与附着颗粒的微织构表面润湿特性的关联性。本研究的结果表明:固体表面附着颗粒时,润湿过程中的界面接触角具有一定的时间依赖性,即表现出一种先迅速减小后趋于稳定的变化趋势;附着颗粒的光滑原始表面的固液平衡接触角的变化趋势则是随着颗粒粒度的增大而减小,随着颗粒质量的增大而减小,随着下落液滴体积的增大而增大;同时在润湿过程中发现了颗粒捕捉现象,包括颗粒吸附现象和颗粒团聚现象;附着颗粒的微织构表面的润湿规律则表现出了接触角随着附着颗粒数目的增加而先增大后减小,随着润湿液滴体积的增大而增大的趋势。此外,附着颗粒的微织构表面的润湿特性受到了表面微凹坑形状和方向的影响,并与三维形貌表征参数中的S_(ku)、S_(sk)、S_(tr)、S_(al)、S_(dq)、S_(dr)、S_(da)、S_(dv)等之间表现出了极强的规律性。
[Abstract]:The wetting phenomenon is affected by the chemical composition, surface microstructure and working conditions of solid materials. The effect of particles attached to solid surface on the interfacial wetting characteristics has been paid more and more attention by scholars. In this paper, the relationship between particles and wetting properties of smooth original surface and microtexture surface and the effect of three-dimensional morphology parameters on the wetting properties of microtexture surface of attached particles are investigated. In this paper, seven groups of surfaces with different microstructure, including smooth original surface, were prepared by laser marking technique with 45 steel. By changing the particle size, mass and number of particles on the attached surface, The wetting experiments of droplet volume on seven groups of surfaces were carried out, and the effects of particles on the wetting characteristics of smooth original surface and microtexture surface were investigated respectively. The surfaces of different microtexture were measured by Talysulf CCI Lite contactless three-dimensional optical profilometer, and the suitable 3D morphology characterization parameters of ISO25178 series were selected to characterize the surface. The relationship between some three-dimensional morphology parameters and the wetting characteristics of microtexture surface of attached particles was also investigated. The results of this study show that the contact angle of the interface in the wetting process is time-dependent when the particles are attached to the solid surface, that is to say, it shows a trend of rapid decrease and then stable change. The change trend of solid-liquid equilibrium contact angle on the smooth original surface of attached particles decreases with the increase of particle size, decreases with the increase of particle mass, and increases with the increase of falling droplet volume. At the same time, the phenomenon of particle capture, including particle adsorption and particle agglomeration, was found in the wetting process. The wetting law of the microtexture surface of the attached particles shows that the contact angle increases at first and then decreases with the increase of the number of attached particles, and increases with the increase of the volume of wetting droplets. In addition, the wetting properties of the microtexture surface of the attached particles are affected by the shape and direction of the micropits on the surface, and the wetting properties of the microtextured surface of the attached particles are affected by the shape and direction of the micropits on the surface. The wetting properties of the microtextured surface of the attached particles are affected by the shape and direction of the micropits. There is a strong regularity between S _ (dr), S _ (da), S _ (dv) and so on.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG178

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