Two-phase ceramics

Yoon, C.K. and Chen, I.W. Superplasticity of two-phase ceramics containing inclusions - zirconia mullite composites , J. Am. Ceram. Soc. 73 (1990) 1555-1565. 

Ishihara, S., etal., Stereographic analysis of grain boundary sliding in superplastic deformation of alumina-zirconia two phase ceramics , Mater. Trans. JIM, 1999, 40, 1158-65. 

The two SiSiC materials, namely SiC-C and SiC-S (supplied by Concord Engineering, Australia and Schunk, Germany, respectively) are two-phase ceramics which consist of high-purity SiC and Si. Fig. 20.3 shows details of... 

Particulate ceramic matrix composites are two-phase ceramics, in which hard refractory particles or fibers are embedded in a ceramic matrix which is usually less creep resistant. Creep begins when the matrix begins to flow hence, the more refractory the matrix, the more creep resistant the composite. However, creep resistance of the composite is determined by both the creep behavior of the matrix and the concentration of particles in the matrix. At low particle concentrations, creep is determined primarily by the rheological... 

In most two-phase ceramics, particle concentrations exceed the rheological threshold discussed above. Therefore, deformation is controlled not by fluid flow, but by direct interactions between the particles that make up the solid. Above the packing threshold, many particles are either in direct contact, or are sufficiently close that particle interactions are important. Processes that occur close to the particle surface dominate the deformation behavior. These processes include solution-precipitation, matrix flow (or matrix percolation) between the particles, and cavitation. 

S. M. Wiederhom, W. Liu, D. F. Carroll, and T.-J. Chuang, Creep Rupture of Two Phase Ceramics, Paper presented at the 91st Annual Meeting and Exposition of the American Ceramic Society, Columbus, OH, April 23-27, 1989, Paper 7-JIII-89. 

C. K. Yoon and I.-W. Chen, Superplastic Flow of Two-Phase Ceramics Containing Rigid Inclusions-Zirconia/Mullite Composites, J. Am. Ceram. Soc., 73[6], 1555-1565 (1990). 

Consider a two-phase ceramic in which there are spherical inclusions... 

FIGURE 24.27 Two-phase ceramics, (a) As sintered and (b) heat treated at 1600°C for 30 hours. ZTA 30% (zirconia-toughened aiumina with 30 voi% YSZ containing 10 moiar% yttria). 

The addition of sufficient alloying component to facilitate a partial stabilization of the cubic phase leads to partially stabilized zirconia (PSZ), which exhibits an improved thermal shock resistance in comparison to fully stabilized zirconia, as well as an excellent fracture toughness. Today, four oxides - CaO, MgO, Y2O3, and Ce02 - are commonly used to produce PSZ which, in fact, is a mixture of cubic and tetragonal/ monodinic phases that can be prepared by heat treatment of the cubic phase. This process is aimed at the development of a two-phase ceramic when the concentration of stabilizing agents is insufficient to produce full stabilization of the cubic structure. 

In Sect. 4.11 the question has been raised whether Liiders bands exist in ceramics. A report specifically refers to the observation of Liiders bands in a two-phase ceramics. The material is high temperature precipitation hardening Y203-partiaUy... 

Figure 4.1.4. Brick layer model for a two-phase ceramic (a) Overall view, showing array of cubic grains, separated by flat grain boundaries, (b) Exploded view of a single cell, showing parallel electrical paths (i) through grains and grain boundaries, and (ii) along grain boundaries.

Figure 4.1.5. Easy path model for a two-phase ceramic (a) Schematic representation of grains separated by a discontinuous grain boundary phase, (b) Series circuit equivalent according to Bauerle [1969]. (c) Parallel circuit equivalent according to Schouler [1979].

Table 10.3 Microstructural Features for Two-Phase Ceramics Produced by Liquid-Phase Sintering for Various Ratios of the Interfacial Energies ysshsi and the Corresponding dihedral angles...

In this paper, the new Monte Carlo Potts model for simulating the sintering process of single- and two-phase ceramic materials is developed and the two-dimensional (2D) grain-growth process is successfully simulated with considering the presence of pores in the green compact. A detailed description of the new Monte Carlo Potts model and simulation procedure is presented. The simulation results are also discussed. 

Monte Carlo Potts model of two-phase ceramic tool materials containing pores... 

In the Monte Carlo Potts model for simulating the sintering process of two-phase ceramic tool materials with pwres, the fine powders and pores are mapped onto a set of two-... 

The equation of state for these simulations is the sum of all the neighbor interaction energies of two-phase ceramic tool materials with pores can be written as ... 

Simulation of microstructural evolution of two-phase ceramic tool material... 

Wahi, R.P., Fracture Behaviour of Two-phase Ceramic Alloys Based on Aluminium Oxide. Trans. Indian Inst, of Metals 34 [2] 89-102 (1981). 

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