Premium
Superplastic Alumina at Temperatures below 1300°C Using Charge‐Compensating Dopants
Author(s) -
Xue Liang A.,
Chen IWei
Publication year - 1996
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1996.tb07903.x
Subject(s) - superplasticity , materials science , dopant , sintering , grain growth , cubic zirconia , diffusion , dissociation (chemistry) , metallurgy , deformation (meteorology) , composite material , grain size , chemical engineering , doping , microstructure , thermodynamics , ceramic , chemistry , physics , optoelectronics , engineering
To achieve low‐temperature superplasticity in alumina, we have introduced charge‐compensating dopants, Ti 4+ and Mn 2+ , which jointly have a high solubility and significantly enhance the diffusion and deformation processes during sintering and forming. Zirconia as a second‐phase pinning agent has also been incorporated to impart microstructural stability against static and dynamic grain growth. The superplastic alumina obtained can be shape‐formed under biaxial tension to 100% engineering strain at temperatures below 1300°C. Deformation characteristics of this alumina at temperatures from 1200° to 1400°C and at strain rates from 4 × 10 ‐6 to 3 × 10 ‐3 /s are described. The origin of enhanced kinetics is attributed to the formation and dissociation of dopant‐defect complexes.