Al-TiO 2 -C晶粒细化剂对工业纯铝细化效果的影响
摘要
The Al-TiO<sub>2</sub>-C grain refiners were synthesized by the <i>in-situ</i> exothermic dispersion method by using TiO<sub>2</sub>,C and Al powders as raw materials. The microstructure of Al-TiO<sub>2</sub>-C refiners with different C/TiO<sub>2</sub> was investigated by SEM, XRD and EDS. Grain refining test was carried out on industrial pure aluminum. The results show that Al-TiO<sub>2</sub>-C refiners are composed of Al<sub>3</sub>Ti,TiC and Al<sub>2</sub>O<sub>3</sub>. When the mole ratio of C to TiO<sub>2</sub> is between 1:25 and 1:20, the amount of Al<sub>2</sub>O<sub>3</sub> is moderate and its distribution is relatively dispersive. An excellent grain refining performance is obtained when adding 0.2% (mass fraction) Al-TiO<sub>2</sub>-C refiner with C/TiO<sub>2</sub> is 1:20, the average grain size is about 142μm and there is no refining recession when holding 1h.