铝热反应制备纳米晶Fe_3Al过程中过冷度对晶粒尺寸的影响

Effects of Under-Cooling Rate on Grain Size in Nano-crystalline Fe_3Al Alloy Prepared by Aluminothermic Reaction

利用C语言计算了铝热反应制备的纳米晶Fe3Al材料均质形核的相关热力学参数和纳米晶材料在不同条件下的平均晶粒尺寸,并通过试验对结果进行验证。结果表明,在形核率一定的情况下,Fe3Al的长大速率随过冷度的增大而增大;Fe3Al的平均晶粒尺寸在过冷度超过330K后均处于纳米级,其随过冷度的增大而逐渐减小,且当达到一定过冷度时,平均晶粒尺寸趋于一致,约37nm,该值与试验测定结果相符合。

Relevant thermodynamic parameters of homogeneous nucleation in aluminothermic reaction prepared bulky nano-crystalline Fe3Al and average grain size in the alloy at different conditions were calculated by C language, and verification experiment was conducted. The results show that at a steady nucleation rate, the growth rate of Fe3Al alloy is increased with increasing in under-cooling rate. Average grain size of Fe3Al exhibits nano-grain with under-cooling rate more than 330 K, and it is gradually decreased towards steady value of approximately 37 nm with increasing in under-cooling rate, which is well in agreement with experimental ones.