Our research was devoted to the fabrication of aluminum matrix composite reinforced by carbon fibers. It is difficult to create this kind of composites, because the molten aluminum does not wet the surface of the carbon. There are several methods to improve the wettability between the two phases, such as overheating, using vacuum, or using molten salts as secondary phase. In our research work, we used molten salts to ensure both the dissolution of the oxide layer from the surface of the molten aluminum, and both the prevention of further oxidation. As a result, a real C-Al interface evolved, and the wetting rate of the two phases is improved. During the research, we examined KI (potassium iodide) - K2TiF6 (potassium hexafluoro-titanate); KCl (potassium chloride)- K2TiF6 and KI-KCl- K2TiF6 salt compositions.
First of all, we investigated how the surface of the glassy carbon and graphite is wetted by molten aluminum under this molten salt mixtures. During these experiments, we determined which salt/Al mass ratio and K2TiF6 concentration is eligible to reach the perfect wettability (meaning contact angle of Θ=0°).
Also, the effect of the holding time was studied at fixed salt/Al mass ratio and fixed K2TiF6 concentration for the KI - K2TiF6 system at a fixed temperature of 800 °C.