Effect of Grain Boundaries

There is a large literature discussing the effects of grain boundaries on plastic deformation. The essential effects for clean boundaries have just been discussed, but there are many additional effects when the boundaries are contaminated with impurities and precipitates. All this will not be discussed further here. Books that have differing viewpoints on grain boundary effects are Baker (1983), and Meyers and Chawla (1998). 

In this section we illustrate the effect of grain boundaries on the conductivity of thin hlms of the TTF-based molecular metals TTF-TCNQ and TTF[Ni(dmit)2]2-In general the existence of grain boundaries hinders the metallic behaviour, inducing semiconducting-like activated conduction (<7rt < 10 cm ) because... 

Figure 4.42 Self-diffusion coefficient in single and polycrystalUne silver, illnstrating the effect of grain boundary diffnsion, especially at lower temperatnres. From K. M. RaUs, T. H. Conrtney, and J. Wulff, Introduction to Materials Science and Engineering. Copyright 1976 by John Wiley Sons, Inc. This material is nsed by permission John Wiley Sons, Inc.

K.T. Aust and J. W. Rutter. Effect of grain boundary mobility and energy on preferred orientation in annealed high purity lead. Trans. AIME, 224 111-115, 1962. 

The overall diffusivities measured in silver are shown in Figure 9.10. It should be noted that the effects of grain boundary diffusion are observable only at low... 

Nakatani, K., Nagayama, H., Yoshida, H., Yamamoto, T., and Sakuma, T., The effect of grain boundary segregation on superplastic behavior in cation-doped 3Y-TZP , Scrlpta Mater., 2003, 49, 791-5. 

This must result in the formation of the layers with uneven interfaces, i.e. the layer thickness becomes irregular. The effect of grain boundary diffusion is clearly most profound in compound layers of columnar structure, with the grains extending from one layer interface to another. In fine-grained structures of constant grain size, it can hardly play any significant role. 

M.J. Verkerk, B.J. Middelhuis and A.J. Burggraaf, Effect of grain boundaries on the conductivity of high purity Zr02-Y203 ceramics. Solid State ionics, 6 (1982) 159-170. 

The detrimental effects of grain boundaries on cell performance depend on their density and on their electrical activity, which depends on their decoration... 

In this paper, thermoelectric figure of merit for n-type sintered materials of SiGe and PbTe has theoretically been estimated considering effects of grain boundaries on carrier mobility and Seebeck coefficient based on a model. 

R. Ishibashi, T. Horiuchi, J. Kuniya, M. Yamamoto, S. Tsurekawa, H. Kokawa, T. Watanabe, T. Shoji, Effect of grain boundary character distribution on stress corrosion cracking behavior in austenitic stairUess steels. Mater. Sci. Forum 475-479 (2005) 3863—3866. 

Paladino AE, Coble RL (1963) Effect of grain boundaries on diffusion-controlled processes in aluminum oxide. J Am Ceram Soc 46 133-136... 

Dericioglu AF, Kagawa Y (2003) Effect of grain boundary microcracking on the light transmittance of sintered transparent MgAl204. J Eur Ceram Soc 23 951-959... 

Balluffi, R. W. and Seigle, L. L., Effect of grain boundaries upon pore formation and dimensional changes during diffusion, Acta Metall., 3, 170-77, 1955. 

Wang, S.-M., Effect of grain boundary structure on diffusion induced grain boundary migration in BaTi03, MS Thesis, KAIST, Daejeon, 2003. 

EFFECT OF GRAIN BOUNDARY ENERGY ON PORE SHRINKAGE... 

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