Estimate of the activation energies for boundary diffusion from rate-controlled sintering of pure alumina, and alumina doped with zirconia or titania

Journal Article · Tue May 01 04:00:00 EDT 1990 · Journal of the American Ceramic Society; (USA)

DOI:https://doi.org/10.1111/j.1151-2916.1990.tb05175.x· OSTI ID:6021927

Wang, J; Raj, R ^[1]

---

1. Cornell Univ., Ithaca, NY (USA). Dept. of Materials Science and Engineering

Sintering experiments at constant heating rates were employed to estimate the activation energy for sintering in alumina and in alumina containing 5 vol% zirconia or 5 vol% titania. Grain growth, which can complicate the analysis of sintering kinetics data, was suppressed by using uniformly and densely packed grain compacts prepared by colloidal processing. Grain-boundary diffusion is believed to have been the dominant sintering mechanism. The activation energies were 440 {+-} 40 kJ/mol for pure alumina, 585 {+-} 40 kJ/mol for alumina (titania), and 730 {+-} 60 kJ/mol for alumina (zirconia). The alumina and alumina (titania) results are in agreement with the values reported in the literature. The possibility that the higher activation energies for doped alumina reflect a stronger bonding at alumina interfaces in the presence of zirconium and titanium is discussed.

• OSTI ID: 6021927
• Journal Information: Journal of the American Ceramic Society; (USA), Journal Name: Journal of the American Ceramic Society; (USA) Vol. 73:5; ISSN 0002-7820; ISSN JACTA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400101 -- Activation
Nuclear Reaction
Radiometric & Radiochemical Procedures
640302 -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ACTIVATION ENERGY
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
ATOM TRANSPORT
CHALCOGENIDES
CHEMICAL REACTION KINETICS
COLLOIDS
CONTROL
CRYSTAL DOPING
CRYSTAL STRUCTURE
DIFFUSION
DISPERSIONS
ENERGY
FABRICATION
GRAIN BOUNDARIES
KINETICS
MICROSTRUCTURE
NEUTRAL-PARTICLE TRANSPORT
OXIDES
OXYGEN COMPOUNDS
PROCESS CONTROL
RADIATION TRANSPORT
REACTION KINETICS
SINTERING
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES