摘要
以废旧硬质合金和可溶性钇盐为原料,采用固-液掺杂,通过球磨将钇源引入钨钴氧化物粉末中,再经过两步还原制备纳米WC-Co复合粉。采用扫描电子显微(SEM)、能谱仪(EDS)与X射线衍射(XRD)分别表征各阶段所获得的粉体的微观形貌、物相组成,分析了氧化钇对紫钨长径比的影响及其作用机制,同时分析了氧化钇对合成纳米WC-Co粉体粒度的影响规律。试验表明,氧化钇的掺杂影响了WO2.72特定晶面的能量,促进WO2.72沿(010)晶面择优生长;试样掺杂氧化钇后,其反应活性变大,使(010)晶面的形核驱动力要大于其他晶面。因此,制备的WO2.72棒更加细长。与未掺杂氧化钇的试样相比,其棒的直径由200 nm减小到140 nm,长度增加了约1倍。此外,在碳化反应过程中,均匀分散的氧化钇增大了WC的非均匀形核率,并阻碍了WC-Co粉体颗粒扩散迁移,从而阻止其合并长大,使得最终合成的WC-Co复合粉具有均匀的粒度分布,平均粒径约为90nm。
Nanoscale WC-Co composite powder was prepared via two-step reduction process using waste cemented carbide and soluble yttrium salt as raw materials.Among them,yttrium source was introduced into the tungsten cobalt oxide powder via solid-liquid doping alter ball milling.The phase composition and nicrostructure of the powder obtained at each stage were characterized via scanning electron microscopy(SEM),energy dispersive spectrometer(EDS)and X-ray diffraction(XRD),respectively.The effects of yttrium oxide on the growth mechanism and aspect ratio of WO2.72were analyzed.The results showed that the doping of yttrium oxide affected the energy of the specific crystal plane of WO2.72,which accelerated a preferential growth along the(010)direction.The activity of the sample would be increased after doping yttrium oxide,and the nucleation driving force of(010)crystal plane was larger than that of other crystal planes,which would decrease the diameter of WO2.72 rods.The diameter of the rods decreased from 200 to 140 nm,and the length of the rod was doubled as compared with that of the undoped yttrium oxide.In addition,the uniformly dispersed yttrium oxide increased the non-uniform nucleation rate of WC and inhibited the diffusion and migration of WC-Co powder particles in the process of carbonization reaction,thus preventingthem from merging and growing.Therefore,the synthesized WC-Co composite powder had a homogeneous particle size distribution with the average size of about 90 nm.
作者
刘柏雄
杨高玲
邝梦杰
尚宜生
朱根松
杨斌
Liu Baixiong;Yang Gaoling;Kuang Mengjie;Shang Yisheng;Zhu Gensong;Yang Bin(Institute of Research and Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China;School of Materials Science and Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China;College of Applied Science,Jiangxi University of Science and Technology,Ganzhou 341000,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2020年第1期26-33,共8页
Chinese Journal of Rare Metals
基金
国家自然科学基金项目(51664023)
江西科技厅基金项目(20142BAB216010)
赣州市创新人才项目(20170215)资助.
关键词
固-液掺杂
还原碳化
WC-Co复合粉
solid-liquid doping
reduced carburization
WC-Co composite powder
