高金属含量NiFe_2O_4基金属陶瓷在880℃空气中的氧化行为  

Oxidation behavior of NiFe_2O_4 based cermets with high metal content at 880 ℃ in air

作　　者：熊慧文[1] 李志友[1] 陶玉强[1] 周科朝[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：《粉末冶金材料科学与工程》2012年第4期468-474,共7页Materials Science and Engineering of Powder Metallurgy

基　　金：国家重点基础研究发展规划("973"计划)资助项目(2005CB623703);国家自然科学创新团队基金资助项目(50474051)

摘　　要：采用冷等静压和N2气氛烧结技术制备相对密度为97%的40(50Ni-Cu)/(10NiO-NiFe2O4)金属陶瓷,在880℃空气气氛中进行氧化实验。采用XRD、SEM和EDS对烧结及氧化样品的物相组成和显微结构进行分析,并对该金属陶瓷的氧化机理进行探讨。结果表明:该金属陶瓷氧化层厚度与氧化时间呈抛物线规律;氧化膜连续、致密,可分为内、中、外3层:外层为外氧化,由氧化铜和氧化亚镍组成的双层结构,中层为大块状的氧化亚镍分散在铁酸镍基体中的致密层,能有效阻碍元素的扩散,内层为少量富Cu的金属相发生内氧化的多孔层。40（50Ni-Cu）/（lONiO-NiFe204） cerrnets with relative density of 97% have been prepared by cold isostatic pressing--N2 atmosphere sintering process. The oxidation experiment of 40（50Ni-Cu）/（lONiO-NiFe204） cermets was carried out at 880 ℃ in air atmosphere. The phase composition, microstructure of the sintered and oxidized specimens were investigated by X-ray diffraction （XRD）, scanning electron microscope （SEM） and energy dispersion spectrometer （EDS）, and the cermets oxidation mechanism was also discussed in detail. The experimental results show that dependence of oxide layer thickness of the cermets on oxidation time fits a parabola relationship. The oxidation film of 40（50Ni-Cu）/（10NiO-NiFe204） cermets is continuous and dense, and the film consists mainly of three layers. The outer double-layer is composed of CuO and NiO, the dense interlayer is massive nickel oxide dispersed in nickel ferrite matrix which can effectively prevent the diffusion of the elements, the inner porous layer is a little amount of inner oxidized Cu-rich metal phase.

关 键 词：铁酸镍 金属陶瓷 CU-NI合金 氧化 

分 类 号：TF821[冶金工程—有色金属冶金]