The Grain Altic Refiner

In this paper, it is mainly studied a technology to produce Al-Ti-C grain refiner and its grain refining properties. In order to promote the formation of TiC , Ce is added to molten aluminum and the dynamical model of Ce's promoting the formation of TiC was set up according to thermodynamics conditions and kinetic theory of melt chemical reaction. The results show that:1 the optimal time of producing Al-Ti-C grain refiner is decided by the reacting time of Al and K₂TiF₆,which is generally 5-10 min. according to the coefficient of carbon, the optimal technology is .the optimal time is 5 minute, the optimal temperature is no lower than 850℃,the optimal time of rotating is 3 minute .2 When the additions of Ce are lower than 0.3wt%, the formation of TiC is promoted at the temperate of 800 ℃, and the additions of Ce are no smaller than 0.3wt%, it is not.3 the dynamical model of Ce's promoting the formation of TiC was set up according to thermodynamics conditions and kinetic theory of melt chemical reaction and the theory of surface tension. Because Ce is active element of surface of molten Al, When Ce is added to molten aluminum, Ce will lower the surface tension of molten aluminum, which promote the wettability of carbon with molten aluminum. Therefore, TiC is easily formed in molten aluminum.4-. The mechanism of high purify aluminum refined by Al-Ti-C master alloy was : the cluster of TiC particles, which are surrounded by a thin layer enriched in Ti ,was in the center of grain. The composition of the thin layer enriched in Ti perhaps is Al3Ti...