Sintering and characterization of yttria-stabilized cubic zirconia with alumina derived from solid solution

Electrical properties of the grain boundaries of oxygen ion conductors: Acceptor-doped zirconia and ceria

“…Fig. 34), predominantly at grain boundaries [185][186][187][188][189][190][191][192][193][194][195][196][198][199][200][201], but also reportedly within the ZrO 2 grains [193]. Some of the Al 2 O 3 precipitates are accompanied by pores and/or amorphous phases (see e.g.…”

“…37 and 38) [40,46,186,187,200]; excessive additions of Al 2 O 3 (e.g. >5 wt.%) always result in a decrease of both the bulk and grain-boundary conductivities [187][188][189][190][191]194,195,197,199,200]. (4) The Al 2 O 3 addition within the solubility limit increases the activation energies for the bulk conductivity (E bulk a ) and the grain-boundary conductivity (E gb a ) (see e.g.…”

Phase transformation studies on YSZ doped with alumina. Part 1: Metastable phases

“…Extra addition of Al 2 O 3 above solubility limit until 5 wt% increases the bulk resistivity and reduces the resistivity of the grain boundaries [13,14]. Excessive addition of Al 2 O 3 more than 5 wt% brings about further increase in the bulk and grain boundary resistivity [15][16][17]. It has been found that oversaturated Al 2 O 3 segregates [9] and forms precipitates predominantly at grain boundaries [18,19], but also reportedly within the ZrO 2 grains.…”

Dense Amorphous Zirconia–Alumina by Low‐Temperature Consolidation of Spray‐Pyrolyzed Powders

“…Consolidation of particulate nanocrystalline and other metastable ceramics into dense forms requires activation in the form of high temperature, static or dynamic loading, or a combination of these. Such activation also triggers transformation to a more stable phase and grain growth, [7][8][9][10][11][12][13][14][15][16][17][18][19][20] leading to the loss of the initial desired structure by the time full density is attained. On the other hand, conditions that allow the desired metastable phase or nanometric grain size to be retained may not be adequate for complete densification.…”