添加La2O3对粉煤灰合成Al2O3-SiC复合粉体的影响

Effect of La_2O_3 Addition on Synthesis of Al_2O_3-SiC Composite Powders from Fly Ash

以粉煤灰和活性炭为原料,通过碳热还原反应在Ar气氛下合成Al_2O_3-SiC粉体,探究了一条低成本合成Al_2O_3-SiC粉体的可行途径。研究了添加La_2O_3对合成过程的影响。采用XRD和SEM表征了材料的物相组成和显微形貌。结果表明:当粉煤灰与活性炭质量比为100∶44,在1 550℃下保温5h,添加6%(质量分数)的La_2O_3时,可合成性能良好的Al_2O_3-SiC粉体,颗粒分布均匀,平均粒径为0.5~1μm,较不添加La_2O_3合成温度降低约50℃。

Al2O3-SiC powders were synthesized by carbothermal reduction reaction in an argon atmosphere,with fly ash and activated carbon as raw materials.It provides a feasibility route with low-cost to the synthesis of Al2O3-SiC powders.The influence of La2O3 addition on the synthesis process was studied.The phase composition and microstructure of the powders were characterized by XRD and SEM.Results showed that the Al2O3-SiC powders could be synthesized at 1 550 ℃for 5h,when the mass ratio of fly ash to activated carbon was 100∶44with addition of 6% La2O3（mass fraction）.The powders had good performance,uniform particle distribution,and the average particle size was about 0.5-1μm.The synthesis temperature of composite powder with La2O3 was 50 ℃lower than that of the mixture without La2O3.