Effect of Si-impurity on the abnormal grain growth behaviour in Y-doped alpha-Al2O3

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Abstract

Y-doped alumina was sintered under ultra-pure experimental conditions to full density without experiencing abnormal grain growth (AGG). Yttrium was fairly homogeneously distributed at the grain boundaries with the average value of =5.4±0.7 at./nm2. However, AGG was observed in Si-contaminated Y2O3-doped alumina samples. At the early stages of AGG exaggeratedly grown alumina grains had curved, “rough” grain boundaries. At later stages of AGG evolution, faceted grain boundaries with thick grain boundary films developed. Frequently observed Y-Al-O precipitates in clean Y2O3-doped alumina specimen were YAP phase. On the other hand, only, YAG phase was present in SiO2-contaminated Y2O3-doped alumina samples. Presence of Si appeared to have facilitated the formation of the complex YAG –phase.

Available Versions of this Item

• Grain Growth and Interface Chemistry in a polycrystalline Alumina with Y, Si, and Ca Impurities. (deposited 16 Oct 2005 03:00)
  • Effect of Si-impurity on the abnormal grain growth behaviour in Y-doped alpha-Al2O3. (deposited 31 Oct 2007 14:52) [Currently Displayed]