導(dǎo)電性和耐蝕性
(中南大學(xué) 粉末冶金國(guó)家重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 在氧分壓約為100 Pa的氮?dú)夥障聼Y(jié)制備了摻雜Y2O3、Yb2O3 的10Cu-(NiFe2O4-10NiO)金屬陶瓷，并對(duì)其進(jìn)行導(dǎo)電性能測(cè)試和10 h (Na3A1F6-Al2O3 體系中)鋁電解實(shí)驗(yàn)。采用XRD、SEM 和EDS分析稀土氧化物以及其與陶瓷基體反應(yīng)產(chǎn)物的分布，考查電解實(shí)驗(yàn)后材料表層顯微結(jié)構(gòu)變化尤其是金屬相的流失情況，評(píng)價(jià)稀土氧化物的添加對(duì)金屬陶瓷電解初期腐蝕行為的影響。結(jié)果表明：摻雜稀土氧化物均使NiO相呈連通跡象，摻雜Yb2O3 金屬陶瓷晶粒較未摻雜的粗大，其與陶瓷相反應(yīng)生成物成點(diǎn)線狀分布于NiFe2O4 相晶界，Y2O3 與陶瓷相反應(yīng)生成物則分布于NiO與NiFe2O4相間；所制備材料具有半導(dǎo)體特征，隨著稀土氧化物的摻雜，材料導(dǎo)電性呈下降趨勢(shì)；摻雜稀土氧化物尤其是Yb2O3有利于提高材料的耐蝕性能。
關(guān)鍵字: 鐵酸鎳；導(dǎo)電性；耐蝕性；稀土氧化物
10Cu-(NiFe2O4-10NiO) inert anode doped Yb2O3 or Y2O3
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:10Cu-(NiFe2O4-10NiO) cermets doped Y2O3, Yb2O3 were prepared by sintering in the nitrogen atmosphere with oxygen partial pressure of about 100 Pa. The electronic conductivity of cermets was tested and 10 h (Na3A1F6-Al2O3 system) aluminum experiments were carried out. The distributions of rare earth oxides and the reaction products with ceramic matrix were analyzed by XRD, SEM and EDS. The effects of rare earth oxides on the corrosion resistance of cermets were evaluated by the change of microstructure of the anode surface after electrolysis, particularly the loss of metal phase. The results show that the NiO phase became more continuous after doping. The grains coarsen after doped Yb2O3 than undoped and the reaction products phase distributes in the NiFe2O4 grains boundary in the term of point line. However, the reaction product of Y2O3 and ceramics phase distributes in the NiO and the NiFe2O4 grain boundary. The prepared material has semiconductor characteristics and the electronic conductivity decreases with the rare earth oxides doping. Rare earth oxides doping help to improve the corrosion resistance of materials, particular Yb2O3.
Key words: NiFe2O4; conductivity; corrosion resistance; rare-earth oxide
