Published online by Cambridge University Press: 21 February 2011
The spherulitic growth of graphite from the melt is described in terms of instability mechanisms. Initially a pyramidal form grows which becomes unstable on the bounding face and a stellar polyhedral form results. The number of polyhedral facets increases in growth and the polyhedral apex angle decreases with the decrease of undercooling due to recalescence. Finally a rounded spherical form is produced.
The observations are taken from different experimental programmes, and from observations reported in the literature. Some comparison is also made with the behaviour of silicon under similar growth conditions.