微孔陶瓷管孔隙率的测定及表面润湿性研究

摘要

采用压汞法对由热压成型法自行制备的微孔陶瓷管孔隙结构进行研究，得到陶瓷管膜的孔隙分布。采用自行研制的三相界面测定仪测量了常见的低温金属锡与刚玉陶瓷管膜在240~640℃内的表观润湿现象，在该温度范围内锡与陶瓷管膜的接触角均大于150°，两者润湿性很差。依据图像处理技术和理论计算，提出一种测量多孔表面液滴渗透速度的方法，推导出液滴向陶瓷管微孔内渗透的速度方程。并以油滴进行实验，实验发现渗透过程中液滴首先会进行铺展，并且一段时间内维持其铺展半径直至最终完全渗入。%Pore structure of porous ceramic tube prepared by the hot forming method is studied by mercury method to obtain pore distribution of ceramic membrane. Self-developed three-phase interface analyzer is used to measure the wetting phenomena of tin which is one of the low melting point metals on the alumina ceramic tube membrane at the temperature from 240℃to 640℃. It is found that the contact angle of tin on ceramic tube membrane at the range of temperature is greater than 150 °, and the wettability of the both is poor. Based on image processing technology and theoretical calculations, a method to measure penetration rate of droplets on porous surface is proposed and a velocity equation of the droplets which penetrate to the porous ceramic tube is deduced. The oil droplet is tested to find out that the droplet spreads firstly during infiltration process and it maintains its spreading radius for a period of time until it fully penetrates into ceramic tube membrane.