Microstructure characterization and electrical conductivity of electroless nano Ni coated 8YSZ cermets
Microstructure characterization and electrical conductivity of electroless nano Ni coated 8YSZ cermets
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DOI：
10.1016/j.surfcoat.2007.09.012
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发表时间：
2008-02
影响因子：
5.4
通讯作者：
A. Rahman;Jong-hee Kim;Kap-Ho Lee;Byong-Taek Lee
中科院分区：
文献类型：
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作者：
A. Rahman;Jong-hee Kim;Kap-Ho Lee;Byong-Taek Lee
采用普通化学镀液制备了Ni-8YSZ （ni - 8mol %钇稳定氧化锆）复合纳米粉体，不使用任何昂贵的增敏剂。HRTEM显微图表明，Ni纳米颗粒在8YSZ表面的包覆形貌呈点状、不连续分布，Ni纳米颗粒呈结晶相。通过改变化学镀液中衬底粉末的添加量，复合粉末中Ni的含量在36 ~ 51 wt.%之间变化。将这些涂层粉末在1300℃下单轴压制烧结2 h，制备棒状样品。当Ni含量在41%或更高时，立方(c)-氧化锆在烧结时部分解离成单斜(m)-氧化锆，并随着Ni含量的增加而增加。在H2+Ar气氛中还原后的Ni-YSZ陶瓷微观结构表现为微观孔隙度和亚微米孔隙度双重尺度。Ni-8YSZ金属陶瓷样品表现出金属导电行为，证明了所合成的纳米复合材料的渗滤能力。
Using a common electroless bath, Ni-8YSZ (Ni-8 mol% yttria stabilized zirconia) composite nano powder have been synthesized without use of any expensive sensitizing agent. HRTEM micrographs indicated that the coating morphology of Ni nano particles on the 8YSZ showed a spotty, discontinuous distribution and the Ni nano particles appeared as a crystalline phase. The amount of Ni in the composite powders was varied from 36–51 wt.% by changing the substrate powder loading in the electroless bath. Bar type samples were prepared by uniaxial pressing and sintering at 1300 °C for 2 h with these coated powders. The cubic (c)-zirconia was found to partially dissociate into monoclinic (m)-zirconia on sintering with Ni content 41% or higher and also increases with the increase of Ni content. The microstructure of each Ni-YSZ cermet after reduction in a H2+Ar gas atmosphere showed dual scale porosity (micro and submicron porosity). The Ni-8YSZ cermet samples showed metallic electrical conduction behavior, proving the percolation capability of the synthesized nano composite.