Model of the Crystallization Process

As spheres bounce off each other without any adhesion or loss of energy, they exist most naturally in a random state, like a gas. But as the spheres are 

Although the face-centered cubic crystal is the one that is most stable, having the lowest energy, it was surprising to find that this phase was not the first to be nucleated, hi fact, the body-centered cubic, i.e. bcc lattice, was the one that 

As the model was observed, small regions of bcc stracture were seen appearing. These crystals were unstable and readily transformed into a faulted mixture of fee and hep structures by a slip of the lattice. Thus fee regions closely followed the appearance of bcc material, with hep lagging behind. 

The nuclei were not rounded or symmetrical but percolated through the surrounding random lattice. Thus, the conventional picture of spherical nuclei shown in many textbooks was proved false in these simulations. Slow conversion and growth of the nuclei occurred, but with an unpredictable path, giving differing amounts of fee and hep. There seemed to be no one single pathway through to the final stable fee structure. 

As the crystal regions began to dominate, with the random phase disappearing, the development of fee stracture became spasmodic as sudden conversions of material took place. These jumps are seen in the simulation of 64,000 particles shown in Fig. 5.15. 

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