Artigo de peri??dico
Porous 8YSZ ceramics prepared with alkali halide sacrificial additives
Registro en:
1996-1944
9
16
10.3390/ma16093509
0000-0002-8598-279X
0000-0001-9219-388X
59.2
67
Autor
DIAZ, JULIO C.C.A.
MUCCILLO, ELIANA N. dos S.
MUCCILLO, REGINALDO
Resumen
8 mol% Y2O3
-stabilized ZrO2
(8YSZ) ceramics were prepared with KCl and LiF additions
to obtain porous specimens with high skeletal density. Thermogravimetric and differential thermal
analyses (TG/DTA) were carried out on 8YSZ and on 8YSZ mixed to 5 wt.% KCl or 5 wt.% LiF as
sacrificial pore formers that were thermally removed during sintering. The melting and evaporation
of the alkali halides were evaluated by differential thermal analysis. Dilatometric analysis was also
carried out following the same TG/DTA temperature profile with results suggesting rearrangement
of the 8YSZ particles during LiF and KCl melting. The dilatometric data of 8YSZ green pellets
mixed to KCl or LiF exhibited an initial expansion up to the melting of the alkali halide, followed by
shrinkage due to sintering evolution with grain growth and pore elimination. The time that the alkali
halide molten phase was kept during sintering was found to be an important parameter for obtaining
8YSZ-sintered specimens with specific pore content; bulk density and open porosity could then be
tuned by controlling the time the alkali halide remained liquid during sintering. Scanning electron
microscopy images of the pellet fracture surfaces showed pores that contributed to increasing the
electrical resistivity as evaluated by impedance spectroscopy analysis. Funda????o de Amparo ?? Pesquisa do Estado de S??o Paulo (FAPESP) Conselho Nacional de Desenvolvimento Cient??fico e Tecnol??gico (CNPq) FAPESP: 17/11937-4; 13/07296-2; 20/05250-9; 18/13620-0 CNPq: 402966/2021- 0; 302357/2018-1; 305889/2018-4