Interaction between liquid Al-10 wt% Sr alloy and vitreous carbon substrate (AlSr10/Cv) has been examined by a sessile drop method at a temperature of 800°C for 30 min under vacuum. The wetting and spreading behavior was recorded by high-speed CCD camera with a rate of 10 frame/s. Non-contact heating to the test temperature and the removal of primary oxide from the alloy by capillary purification was applied by squeezing the liquid alloy from a graphite capillary at the test temperature under vacuum directly during wettability test. For comparison, similar test under indentical conditions was also performed with pure Al (99.999%).
The solidified sessile drop couples Al/Cv and AlSr10/Cv were used for detailed structural characterization using light microscopy, scanning electron microscopy, and transmission electron microscopy coupled with EDS analysis. The role of alloying aluminum with strontium on the relationship between wetting properties and interface structure are discussed and compared with thermodynamic predictions.