Journal of Materials Science, Vol.30, No.15, 3791-3798, 1995
Generation of Isothermal Spreading Data and Interfacial Energy Data for Liquid Reactive Metals on Ceramic Substrates - The Copper-Titanium Alumina System
The sessile drop technique is frequently used to evaluate the wettability and spreadability of liquid metals on ceramic substrates. In this study, the spreading kinetics of copper-20 wt % titanium alloys on polycrystalline alumina were evaluated based on measurements of spreading radius versus time. The process of spreading was monitored by an in situ video recording system. The tests were performed using three different initial metal configurations. It was found that conventional sessile drop testing configurations can not be used to generate isothermal spreading kinetics data because of significant spreading during the heat-up cycle from the solid us temperature to the test temperature. An im proved sessile drop technique was developed which eliminated the non-isothermal experience by introducing the liquid copper to the solid titanium/alumina at the desired testing temperature. Using this technique, only a few seconds of data were lost (while the liquid copper dissolved the solid titanium). Because very limited interfacial energy data exist for the copper-titanium/alumina system, especially at higher titanium concentrations, the equilibrium contact angle, the solid-liquid interfacial energy, and the work of adhesion from 1000 to 1300 degrees C are also presented.