Phase transformation studies on YSZ doped with alumina. Part 1: Metastable phases

作者：Nazarpour S^*; Lopez Gandara C; Ramos F M; Cirera A

来源：Journal of Alloys and Compounds, 2010, 505(2): 527-533.

DOI：10.1016/j.jallcom.2010.05.136

• YSZ
• Tetragonal
• Metastable phases
• Alumina segregation

The goal of this study is to clarify the effect of the addition of Al(2)O(3) on the grain boundaries of yttria stabilized zirconia using high resolution transmission electron microscopy. Basically excessive concentration of alumina, which is not solved in YSZ, segregates within YSZ matrix. Alumina segregates as grains between YSZ grains and as particles within YSZ grain boundaries.
t' metastable phase was detected within the grains of the sintered YSZ powders. By adding alumina into the primary YSZ powders and sintering it all together, metastable tetragonal phases appear in the grain boundaries between YSZ and segregated alumina grains. Similar phenomenon was detected in the boundaries of the two neighboring grains of YSZ doped with Alumina. Appearance of these phases might be due to the accumulated strain energies which are generated because of the alumina segregation into grain boundaries and matrix of YSZ. Hence, by controlling the dopant concentration, it could be possible to form YSZ structured by e metastable phase. Fabrication of this material is in the great attention of the high temperature applications due to the high resistive properties of the t' metastable phase against high temperature degradation of the YSZ.

• 出版日期2010-9-3