Grain Growth of Silica‐Added Zirconia Annealed in the Cubic/Tetragonal Two‐Phase Region

Abstract

The grain growth in silica-doped 3-mol%-yttria-stabilized tetragonal zirconia polycrystals (SiO 2 -doped 3Y-TZP) and undoped 3Y-TZP has been examined in the temperature range of 1400°-1800°C. The presence of a SiO 2 phase inhibits rather than promotes the grain growth in 3Y-TZP, particularly at high temperatures. During the grain growth in 3Y-TZP, yttrium ions are partitioned between grains, and the grain growth mechanism can be understood from Ostwald ripening dominated by lattice diffusion of cations. In SiO 2 -doped 3Y-TZP, an amorphous SiO 2 -rich phase exists only in the grain-boundary corners or junctions, not in the grain-boundary faces. The grain growth in SiO 2 -doped 3Y-TZP is controlled by using different mechanisms below and above the eutectic temperature of the zirconia-silica (ZrO 2 -SiO 2 ) system. The glass phase does not have a major role in grain growth below the eutectic temperature, and the grain growth is dominated by a similar mechanism in undoped 3Y-TZP. The grain growth is more effectively retarded by the presence of a SiO 2 phase above the eutectic temperature and is likely to be controlled by a solutionreprecipitation process in the amorphous phase at the grain-boundary corners or junctions.

Fracture toughness (KIC), hardness, sintering and grain growth behaviour of 8YSCZ/Al2O3 composites produced by colloidal processing

“…In a dual phase structure, the steady state grain growth would occur such that the growth of one phase is affected by other phase grains i.e. the grain growth is mutually restricted by Zener's pinning because of minor phase grains, as in metallic materials and that the coarsening of the minor phase is approximated by Ostwald ripening then n = 3 can be predicted for lattice-diffusion controlled grain growth [10]. The activation energy for grain growth is calculated from the slope of log ((D n − D n 0 )/t) versus 1/T.…”

Influence of alumina addition on grain growth and room temperature mechanical properties of 8YSCZ/Al2O3 composites

“…In the case of single phase growth, the exponent n usually takes a value of 2 which shows normal grain growth. In a dual phase structure, the steady state grain growth would occur such that the growth of one phase is affected by other phase grains, i.e., the grain growth is mutually restricted by ZenerÕs pinning because of minor phase grains, as in metallic materials and that the coarsening of the minor phase is approximated by Ostwald ripening then n = 3 can be predicted for lattice-diffusion controlled grain growth [8]. The activation energy for grain growth is calculated from the slope of logððD n À D n 0 Þ=tÞ vs: 1=T as shown in Fig.…”

Phase stability and microstructure evolution of yttria-stabilized zirconia during firing in a reducing atmosphere

“…The grain growth behaviour of tetragonal (t) phase during sintering above 1300 8C in air had been investigated [26,31,32,36]. A high Y 3+ segregation within a 10 nm region near grain boundary has been confirmed through a microstructure analysis [31,32].…”