Sintering mechanisms

Conventional Sintering. Ceramic sintering is usually accompHshed by heating a powder compact to ca two-thirds of its melting temperature at ambient pressure and hoi ding for a given time. Densification can occur by soHd-state, Hquid-phase, or viscous sintering mechanisms. 

Ashby pointed out diat die sintering studies of copper particles of radius 3-15 microns showed clearly the effects of surface diffusion, and die activation energy for surface diffusion is close to the activation energy for volume diffusion, and hence it is not necessarily the volume diffusion process which predominates as a sintering mechanism at temperatures less than 800°C. 

Two mathematical models for sintering mechanisms for supported metals have been put forward (1) a particle migration model where particles migrate over the surface of the support, collide and fuse, causing loss in dispersion (e.g. Ruckenstein et al 1984) and (2) an atomic migration model involving the... 

In situ ETEM permits direct probing of particle sintering mechanisms and the effect of gas environments on supported metal-particle catalysts under reaction conditions. Here we present some examples of metals supported on non-wetting or irreducible ceramic supports, such as alumina and silica. The experiments are important in understanding metal-support interactions on irreducibe ceramics. 

J.M. Dynys. Sintering Mechanisms and Surface Diffusion for Aluminum Oxide. PhD thesis, Department of Materials Science and Engineering, Massachusetts Institute of Technology, 1982. 

Suppose that two sintering systems, S and B, are identical in all aspects except their size.15 Each length dimension of system B is A times as large as the corresponding dimension of system S. Under identical conditions and provided that the same sintering mechanism is operative, the ratio of sintering rates can be determined from the relative sizes of the specimens. 

Figure 16.10 Sintering mechanism map for silver powder of radius 100 pm plotted...

Later, Chin et al. [33] continued their work on Pd/ZnO catalysts. They stated that the major drawback of applying copper-based catalysts for mobile fuel processors was the sintering mechanisms at temperatures exceeding 270 °C and the pyrophoricity of copper-based catalysts. The latter is a safety issue regarding accidental exposure of the catalyst to air. 

Rasmussen et al. (2004) SAX Ni-alumina Sintering mechanism + + Distinction between coalescence and atomic migration... 

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