Theory of Diffusion Controlled Growth

Dislocation theory of chirality-controlled nanotube growth.

The periodic makeup of carbon nanotubes suggests that their formation should obey the principles established for crystals. Nevertheless, this important connection remained elusive for decades and no theoretical regularities in the rates and product type distribution have been found. Here we contend that any nanotube can be viewed as having a screw dislocation along the axis. Consequently, its g...

Mixed Diffusion–Controlled Growth of Pearlite in Binary Steel

A kinetic theory for the diffusion–controlled growth of pearlite is presented, which accounts simultaneously for diffusion through the austenite and via the transformation front. The simplified method abandons the need for mechanical equilibrium at the phase junctions and yet is able to explain experimental data on the growth rate of pearlite. Furthermore, unlike previous analyses, the deduced ...

Diffusion–Controlled Growth of Pearlite in Ternary Steels

A theory for the diffusion–controlled growth of pearlite in steels containing manganese is presented and assessed in the light of experimental data. Given the overwhelmingly rapid diffusivity that a substitutional solute has within the transformation front, the growth rate is found to be dominated by diffusion parallel to the interface with austenite as the rate controlling step. The relevant i...

Numerical simulation of diffusion-controlled droplet growth: Dynamical correlation effects.

Diffusion-controlled coarsening (Ostwald ripening) of precipitated Solutions is studied by numerical Simulation. An algorithm is devised which exploits the screening of solute concentration fields, thereby removing the restriction to small Systems of previous work. Simulation of the coarsening of 5000 droplets at 10% volume fraction reveals long-ranged dynamical correlations which broaden the d...

Statistical Theory of Diffusion-Limited Growth in Two Dimensions