【摘要】 以NiO,Fe2O3,Ag粉和微量V2O5为原料,用粉末冶金法制备掺杂V2O5的镍铁尖晶石金属陶瓷惰性阳极,研究V2O5对惰性阳极材料微观形貌和电导率的影响。结果表明:添加V2O5后,V2O5与Fe2O3和NiO形成低熔点的化合物Ni2FeVO6,该物质在烧结过程中呈液相。液相的出现使金属银在陶瓷相中呈细长的线状分布。能谱分析发现:金属相中含有陶瓷相的组成,说明金属相与陶瓷相间的润湿性有所改善。同时,样品的电导率显著提高。当添加2.0%(以质量计)V2O5时,样品的电导率约为无添加剂的Ag/NiFe2O4金属陶瓷样品的7倍,这主要是因为V2O5在烧结过程中形成液相,改善金属相与陶瓷相间的界面相容性,从而改变金属相在陶瓷相中的分布状况。掺杂后,样品的电导率在450～650℃之间发生突变,呈现急剧上升,这可能是由于添加剂诱发NiFe2O4的磁性发生变化,从而导致电导率发生突变。更多还原

【Abstract】 Inert anodes of nickel ferrite-based cermets were prepared by the powder metallurgy method using NiO, Fe₂O₃, Ag, and a little V₂O₅ as raw materials. The effect of V₂O₅ on microstructure and conductivity of the inert anodes was investigated. The results indicate that when the additive V₂O 5 is added, V₂O₅ reacted with Fe₂O₃ and NiO to produce Ni₂FeVO 6, which has a lower melting point. During sintering, Ni₂FeVO 6 became liquid, causing the metal phase silver to be distributed in a slender strip formation. Energy dispersive X-ray spectrometer analysis shows that there is ceramic phase in the metal phase. The facts show V₂O₅ can improve the wettability between metallic phase Ag and ceramics. The conductivity of the samples improves remarkably. When the mass fraction of V₂O₅ was 2.0%, the conductivity of the sample was 7 times of that of samples without V₂O₅. The main reason must be that liquid improved the wettability between metallic phase Ag and ceramics, and the distribution of Ag changed, causing the conductivity to increase. Moreover, a remarkable change of conductivity took place from 450 ℃ to 650 ℃, which are induced the magnetism of NiFe₂O₄ to change by adding V₂O₅, resulting in a remarkable change in conductivity.更多还原