Journal of the Korean Ceramic Society (한국세라믹학회지)

The Korean Ceramic Society (한국세라믹학회)
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Effects of CaO Impurity on Microstructural Evolution during Sintering of Alumina

알루미나의 소결 중 CaO 불순물의 미세구조에 미치는 영향

  • 김상섭 (포항공과대학 재료·금속공학과) ;
  • 백성기 (포항공과대학 재료·금속공학과)
  • Published : 1992.01.01
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Abstract

The effect of CaO impurity on the microstructural evolution during the sintering of ultrapure alumina(>99.999%) was studied under "clean" firing conditions. The sinterability of undoped alumina was low, but its microstructure was maintained uniform. In the case of CaO-doped alumina, the distribution of grain size and that of grain boundary dihedral angle became wider, and facetted pores observed frequently. When MgO was doped in addition to CaO, the sinterability increased drastically and the uniform microstructural characteristics resumed. This study suggests that the effect of CaO is to induce inhomogeneous microstructures presumably by anisotropic segregation to grain boundaries and pore surfaces, and that MgO suppresses the anisotropic segregation of Ca.

Keywords

References

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