共沉淀法制备Co-Y_2O_3复合粉的热力学分析  

Thermodynamic Analysis of Co-Y_2O_3 Composite Powders Prepared by Coprecipitation

作　　者：覃德清[1] 唐建成[1] 叶楠[1] 卓海鸥[1] 师晓燕[1] 吴桐[1] 

机构地区：[1]南昌大学,江西南昌330031

出　　处：《稀有金属材料与工程》2016年第7期1881-1886,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50801037;51071082;51271090;51364036);教育部博士学科点专项基金(20103601110001);教育部长江学者和创新团队发展计划(IRT0730);教育部新世纪优秀人才支持计划(NECT-10-0184);江西省高等学校科技落地计划(12056)

摘　　要：为了制备球形颗粒的Co粉和实现在Co粉中添加Y_2O_3的目的,分析了共沉淀法制备Co-Y_2O_3复合粉前驱体的热力学。通过对Co^(2+)-Y^(3+)-NH_3-C_2O_4^(2-)-H_2O沉淀体系的热力学分析,得到了lg[M]T-p H关系图(M为金属元素)。热力学分析表明:增加草酸根总浓度[C]T和铵根总浓度[N]T会促进Co^(2+)离子的络合,而Yz^(3+)离子只受草酸根总浓度[C]T的影响,随着[C]T的升高Y^(3+)离子沉淀率下降。Co^(2+)离子和Y^(3+)离子沉淀的最佳p H值分别为2~2.5和1.5~2.5。当p H值为2.5时,由共沉淀法制备出簇球状Co-Y_2O_3前驱体,经煅烧和还原后得到球形Co-Y_2O_3复合粉,其颗粒尺寸约为5μm。In order to prepare spherical particles of cobalt powders and to add Y_2O_3 into cobalt powders,the thermodynamics of the precursor of Co-Y_2O_3 composite powders by coprecipitation was analyzed.The lg[M]T-p H diagram was obtained by analyzing the thermodynamics of Co^2＋-Y^3＋-NH_3-C_2O_4^2--H_2 O precipitation system.It is shown that the complexation of Co^2＋ ions is promoted by increasing the total concentration of oxalic acid root [C]T and ammonium root [N]T.The precipitation rate of Y^3＋ ion is only influenced by the total concentration of oxalic acid root [C]T,which declines with the increase of [C]T.The optimum p H values for the precipitation of Co^2＋ and Y^3＋ are 2-2.5 and 1.5-2.5,respectively.The precursor of Co-Y_2O_3 composite powders was prepared by coprecipitation with the p H value of 2.5.The shape of the precursor composite powders is cluster ball with good dispersion.The spherical Co-Y_2O_3 composite powders with uniform size distribution are obtained whose mean particle size is about 5 μm.

关 键 词：共沉淀 热力学分析 Co-Y_2O_3复合粉 

分 类 号：TF123.74[冶金工程—粉末冶金]