REACTIVE WETTING OF LIQUID METALS ON CERAMIC SUBSTRATES

摘要

This paper deals with a well known puzzling observation that sometimes the wetting is improved by a chemical reaction between a liquid and a solid substrate and sometimes just the opposite effect takes place. Here, contact angles of liquid Al on SiO_2 and liquid Ti on Al_20_3 have been measured. The surface and interface structures have been explored by scanning electron microscopy and energy dispersive X-ray spectrometry. According to the experimental observations, it turns out that the volume change of ceramic substrates during reaction plays a key role in the effect of chemical reaction on wetting. If the volume of ceramic substrate decreases after reaction, the wettability is not improved by the chemical reaction.