The Kinetics of Grain-Boundary Groove Growth on Alumina Surfaces

1966 ◽  
pp. 49-60 ◽  
Author(s):  
Wayne M. Robertson ◽  
Roger Chang
Keyword(s):  
Grain Boundary ◽  
Boundary Groove ◽  
Kinetics Of

Inhomogeneous Swelling Near Grain Boundaries in Irradiated Materials: Cavity Nucleation and Growth Saturation Effects

2000 ◽  
Vol 650 ◽  
Author(s):  
S. L. Dudarev
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Nucleation And Growth ◽  
Homogeneous Distribution ◽  
Rate Theory ◽  
Diffusional Growth ◽  
Standard Rate ◽  
Saturation Effects ◽  
Kinetics Of ◽  
Cascade Damage

ABSTRACTThe effect of inhomogeneous nucleation and growth of cavities near grain boundaries illustrates the failure of the standard rate theory to describe the kinetics of phase transformations in irradiated materials under cascade damage conditions. The enhanced swelling observed near grain boundaries is believed to result from the competition between the diffusional growth of cavities and their shrinkage due to the interaction with mobile interstitial clusters. Swelling rates associated with the two processes behave in a radically different way as a function of the size of growing cavities. For a spatially homogeneous distribution of cavities this gives rise to the saturation of swelling in the limit of large irradiation doses.We investigate the evolution of the population of cavities nucleating and growing near a planar grain boundary. We show that a cavity growing near the boundary is able to reach a size that is substantially larger than the size of a cavity growing in the interior region of the grain. For a planar grain boundary the magnitude of swelling at maximum is found to be up to eight times higher than the magnitude of swelling in the grain interior.

An Auger Electron Spectroscopic Study of the Diffusion of Sulfur and Carbon in α-Iron

1977 ◽  
Vol 31 (3) ◽  
pp. 210-213 ◽  
Author(s):  
W. E. Swartz ◽  
D. M. Holloway
Keyword(s):  
Activation Energy ◽  
Grain Boundary ◽  
Diffusion Process ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Boundary Diffusion ◽  
Carbon Migration ◽  
Sulfur Diffusion ◽  
Kinetics Of ◽  
Arrhenius Analysis

Auger electron spectroscopy has been employed to study the diffusion of sulfur and carbon in α-iron. In the temperature range 25 to 500°C carbon preferentially segregates to the surface. From 400 to 700°C sulfur segregates to the surface while carbon is thermally desorbed. An Arrhenius analysis of the sulfur diffusion data yields an activation energy of 14.5 kcal/mol, which is consistent with a grain boundary diffusion process. The kinetics of carbon migration is complicated by the thermal desorption which makes Arrhenius analysis impossible.

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