Hardening in creep of alumina by zirconium segregation at the grain boundary
- National Industrial Research Inst., Nagoya (Japan)
- Japan Science and Technology Corp., Nagoya (Japan)
The effect of zirconium segregation on hardening in the creep of fine-grained alumina was studied by using the tensile creep test. To avoid the effect of zirconia particle dispersion in creep, 100-ppm-zirconium-doped alumina and 1,000-ppm-zirconium-doped alumina were fabricated by using a zirconium-containing precursor. The scanning transmission electron microscopy/energy-dispersive X-ray spectroscopy study revealed that the zirconium was segregated at the alumina grain boundary. Doping even as little as 100 ppm of zirconium caused the hardening effect. The creep rate was further reduced by increasing the amount of zirconium dopant. Although the stress exponent of 2 was not affected by zirconium segregation, the apparent activation energy of the creep was found to be increased, from 520 kJ/mol for undoped alumina to 670 kJ/mol for 100-ppm-zirconium-doped alumina and 760 kJ/mol for 1,000-ppm-zirconium-doped alumina. It was suggested that grain-boundary sliding was accommodated by impurity-drag-controlled diffusional creep.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 554022
- Journal Information:
- Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 9 Vol. 80; ISSN 0002-7820; ISSN JACTAW
- Country of Publication:
- United States
- Language:
- English
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