WETTING OF GRAPHITE BY LIQUID ALUMINIUM
铝液对石墨润湿过程的研究

The wetting of graphite by liquid aluminium was studied by sessile drop method. The results show that in accordance with the variation of contact angle with time, the wetting process may be divided into three dynamic stages: nonwetting, abrupt change and gradual wetting. At the first stage, the contact angle between drop surface covered by aluminium oxide film and graphite substrate was very large; while at the last stage, the formation of Al_4C_3 at the interface of aluminium and graphite led to the decrease of contact angle gradually. The transition point from the second stage to the last one is defined as the "actual contact angle" by the authors, which can be used as an exact indication of wettability. By increasing the temperature, the wet- ting of graphite by liquid aluminium may be improved.