Journal of Inorganic Materials

• Research Paper •     Next Articles

Superplasticity in Ceramics

ZHANG Kai-Feng; CHEN Guo-Qing; WANG Guo-Feng   

  1. School of Materials Science and Engineering; Harbin Institute of Technology; Harbin 150001; China
  • Received:2002-06-10 Revised:2002-09-12 Published:2003-07-20 Online:2003-07-20

Abstract: It is clearly demonstrated that the superplasticity is one of the common properties of fine-grained ceramics at elevated temperatures. The paper reviewed
the major features of superplasticity in ceramics, the deformation characteristics and mechanism of yttria-stabilized tetragonal zirconia polycrystals(Y-TZP), a
typical superplastic ceramic. The reason for the difference in regionⅠbetween high-purity and low-purity Y-TZP was explained, then the effects of impurities
on the apparent stress exponent were found out. The rate controlling mechanism in superplasticity was also analyzed from the point of activation energy. The
superplastic characteristics of Si3N4 covalent ceramics enhanced by intergranular glass phase was studied, hence the role of the intergranular glass
phase in superplasticity was defined. The superplastic behavior of other ceramic materials, including Al2O3, aluminium based composites, covalent ceramic
materials and nano-structured ceramics were also summarized.

Key words: ceramics, superplasticity, deformation mechanism, glassy phase

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