Densification kinetics of nanocrystalline zirconia powder using microwave and spark plasma sintering--a comparative study.
Two-stage densification process of nanosized 3 mol% yttria-stabilized zirconia (3Y-SZ) polycrystalline compacts during consolidation via microwave and spark-plasma sintering have been observed. The values of activation energies obtained for microwave and spark-plasma sintering 260-275 kJ x mol(-1) are quite similar to that of conventional sintering of zirconia, suggesting that densification during initial stage is controlled by the grain-boundary diffusion mechanism. The sintering behavior during microwave sintering was significantly affected by preliminary pressing conditions, as the surface diffusion mechanism (230 kJ x mol(-1)) is active in case of cold-isostatic pressing procedure was applied.
National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
Oleg
O
Vasylkiv
Dmytro
D
Demirskyi
Yoshio
Y
Sakka
Andrey
A
Ragulya
Hanna
H
Borodianska
D003460:Crystallization / Q000379:methods*; D006358:Hot Temperature; D007700:Kinetics; D046911:Macromolecular Substances / Q000737:chemistry / Q000528:radiation effects; D008872:Microwaves; D008968:Molecular Conformation / Q000528:radiation effects; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects / Q000648:ultrastructure*; D010316:Particle Size; D058626:Plasma Gases / Q000737:chemistry*; D011208:Powders; D013499:Surface Properties / Q000528:radiation effects; D015040:Zirconium / Q000737:chemistry* / Q000528:radiation effects*
D046911:Macromolecular Substances; D058626:Plasma Gases; D011208:Powders; D015040:Zirconium; C028541:zirconium oxide