Fabrication and Characterization of Partially Reduced NiO-YSZ Cermets

部分還原氧化鎳－氧化釔安定化氧化鋯陶金之製備與分析

楊志忠(C. C. T. Yang) ； 韋文誠(W. C. J. Wei)

《材料科學與工程》 35卷2期 (2003/06) Pp. 83-90

https://doi.org/10.6409/JMSE.200306.0083

摘要

本研究以乾壓法製備10或40vol%的鎳－氧化釔安定化氧化鋯(Ni-YSZ)陶金。X光繞射結果顯示，燒結溫度爲1300℃時，氧化鎳在氧化釔安定化氧化鋯(YSZ)的固溶量低於5mol%。微結構觀察顯示均勻的雙相微結構，是由氧化鎳或鎳金屬顆粒均勻分布於YSZ的基材中。當燒結溫度由1300℃提高至1600℃時，高溫燒結使得氧化鎳揮發，並於降溫過程中產生凝結顆粒。燒結試樣然後在還原性氫氣氣氛1000℃熱處理，時間爲1~10小時，由於陶金試樣的緻密性提高，使得氧化鎳還原不易，導致部分還原氧化鎳的生成，並產生一具有核－殼的鎳／氧化鎳微結構，呈現奈米尺寸的鎳與氧化鎳的缺陷簇。還原鎳金屬顆粒的尺寸小至20至30nm。分析式電子顯微鏡結果顯示，鎳／氧化鎳與YSZ之界面無相互擴散或新反應物的生成。

關鍵字

鎳－氧化釔安定化氧化鋯 ； 核－殼 ； 奈米尺寸 ； 相互擴散

並列摘要

10 or 40 vol% Ni-YSZ cermets were prepared by die pressing. The XRD results show that the solid solubility of NiO in YSZ should be less than 5 mol% when sintering at 1300℃/1 h. The sintered NiO-YSZ or reduced Ni-YSZ cermets show a uniform two-phase microstructure, consisting of NiO/Ni grains dispersed in the continuous YSZ matrix. When increasing the sintering temperature from 1300℃ to 1600℃, the evaporation of NiO phases takes place at high temperature and condensation of NiO occurs during the cooling process. Ni-YSZ cermets were then annealed at 1000℃ for 1 h to 10 h under 5vol% H2 atmosphere. After the reduction, the denser NiO-YSZ cermets resulted in the formation of partially reduced NiO particles and thus the formation of core-shell microstructures, showing the nano-sized Ni crystals and defect clustering of NiO. The size of nano-sized Ni crystals in the shell structure is in the range of 20-30 nm. No inter-diffusion or reaction between Ni/NiO and YSZ is found in the present research after annealing at 1000℃ for 10 h under 5vol% H2 atmosphere.

並列關鍵字

Ni-YSZ ； core-shell ； nano-sized ； inter-diffusion