On the reaction between Fe-Ti and Fe-C liquids under microgravity

Reaction between liquid Fe-Ti and Fe-C alloys has been studied under microgravity on board an aeroplane during parabolic flights. The two alloys were melted in contact with each other and held for some seconds at a temperature of 1450 degrees C. The samples were melted and solidified during the microgravity period. During the contact of the two liquid alloys, carbon and titanium atoms reacted in the melt and titanium carbides were formed. A carbide containing layer was formed at the interface region between the two liquids on the Fe-Ti side. The thicknesses of the carbide layers were measured. Theoretical calculation of the precipitation kinetics was attempted, and good agreement between the calculated and experimental results was obtained. The effect of alloy composition on the growth rates of the carbide zones was revealed by both experiments and calculations. Supersaturation of the carbide in front of the reaction interface was calculated. Homogeneous nucleation of titanium carbide can readily occur according to the present calculations.