纳米级W-Ni-Fe复合粉末的制备  

Preparation of nano-sized W-Ni-Fe composite powder

作　　者：马运柱[1] 黄伯云[1] 范景莲[1] 熊翔[1] 汪登龙[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金技术》2005年第1期40-43,共4页Powder Metallurgy Technology

基　　金：国家"8 6 3"高新技术资助项目 (2 0 0 2AA30 5 5 0 3)

摘　　要：以喷雾干燥法制备的W Ni Fe复合氧化物粉末为原料 ,在 70 0℃、保温 90min的条件下进行还原 ,制得了纳米级 90W 7Ni 3Fe复合粉末 ,并研究了不同稀土La含量对还原制备纳米级W Ni Fe复合粉末性能的影响 ;采用XRD及SEM分别对所制备的复合粉末进行了物相分析、晶粒尺寸测试和形貌观察 ;并对所制得复合粉末的Fsss粒度、比表面、氧含量、氮含量、碳含量等性能进行了测定与分析。研究结果表明 :不加稀土La时所制得粉末的dBET 为 96 6nm、晶粒尺寸为 2 6 1nm、Fsss为 0 6 4 μm、氧含量为 0 2 3%、氮含量为0 17%、碳含量为 0 0 2 8% ,粉末颗粒为球形或近球形 ,还原粉末由W和γ (Ni,Fe)两相组成 ;添加一定量的稀土La不仅可以有效地抑制晶粒的长大 ,还可以在一定程度上提高粉末的分散性 ;当La的质量分数在 0 0 8%范围内 (占 90W 7Ni 3Fe复合粉末的质量百分数 ) ,随着La含量的增高 ,粉末晶粒尺寸和颗粒粒度逐渐减小 ;添加 0 8%的La可以制得费氏粒度 (Fsss)小于 0 36 μm ,dBET小于 6 0nm ,晶粒尺寸小于 2 2nm的纳米级90W 7Ni 3Fe复合粉末。Nano-sized 90W-7Ni-3Fe composite powder was obtained by reduction of (W,Ni,Fe) composite oxide powder synthesized by spray drying with reduction conditions of 700°C for 90 minutes. The effect of the rare earth element La contents on the properties of the composite powder was studied. Phase composition, grain size and particle morphology of the powder have been measured by X-ray diffraction and SEM. Fsss particle size, specific surface area, oxide content, nitrogen content and carbon content of the reduced powder were also measured and analyzed. The result showed that: 90W-7Ni-3Fe composite powder was synthesized without the rare earth element La with dBET, grain size, Fsss, oxide content, nitrogen content and carbon content were 96.6 nm, 26.1 nm, 0.64 μm, 0.23%, 0.17%, 0.028% respectively. Meanwhile the particle morphology is spherical or nearly spherical, the phase composition of the composite powder reduced are W and γ-(Ni,Fe); Adding some La not only inhibit the grain growth during reduction but also enhance the dispersion of the composite powder; When the La content is under 0.8%, with the increasing of the La content, grain size and particle size of the reduction powder are decreased gradually; nano-sized 90W-7Ni-3Fe composite powder was synthesized by adding 0.8% La with Fsss of smaller than 0.36 μm, dBET smaller than 60 nm and grain size smaller than 22 nm.

关 键 词：纳米级 制备 稀土La 还原 复合氧化物粉末 分散性 添加 复合粉末 碳含量 氧含量 

分 类 号：TF123[冶金工程—粉末冶金] TF125[冶金工程—冶金物理化学]