Growth transformation

Goodman RH, Smolik S (2000) CBP/p300 in cell growth, transformation, and development. Genes Dev 14 1553-1577... 

Figure 3.11 Schematic comparison of dimensional changes that occnr in (a) spinodal and (b) nucleation and growth transformation processes. From W. D. Kingery, H. K. Bowen, and D. R. Uhlmann. Introduction to Ceramics, Copyright 1976 by John Wiley Sons, Inc. This material is used by permission of John Wiley Sons, Inc.

Equation 21.4 forms the basis of the theory for the kinetics of concurrent nu-cleation and growth transformations. Specific cases can be formulated by deriving appropriate expressions for the quantity N)c. 

The Alnico microstructures are prepared by a process which involves spinodal decomposition. In this phase transformation, the high-temperature phase decomposes into two phases, usually known as and a2. Fig. 6.25. A spinodal curve inside the solvus curve separates the regions where either spinodal decomposition (compositions and temperatures inside the spnodal curve) or normal, nucleation and growth transformation (between solvus and spinodal) occur. Spinodal decomposition occurs by periodic composition fluctuations (Burke, 1965) as transformation proceeds, composition fluctuations increase ( i becomes richer in A and 2 in B, for instance), but the spatial periodicity is conserved. 

Figure 6.2 schematically illustrates the differences between a continuous spinodal phase transformation and a discontinuous nucleation and growth transformation. 

Upon quenching a material to induce a partial martensitic transformation, further reduction in temperature will usually induce further martensitic nucleation and growth. Thus, greater transformation is accomplished by deeper and more rapid quenching. This is in contrast to diffusion-based nucleation and growth transformations, where rapid and deep undercooling can prevent phase transformation. 

Baserga, R., Hongo, A., Rubini, M., Prisco, M., and Valentinis, B. 1997. The lGF-1 receptor in cell growth, transformation and apoptosis. Biochimica et Biophysica Acta (BBA)—Reviews on Cancer, 1332, F105-F126. 

At least one local hormone has been shown to inhibit growth transforming mowth factor 6 (TGFB) (Grubeck-Loebenstein et al., 1989 Morris et al., 1988 Tsushima et al., 1988 Wyllie et al., 1991) as in other epithelial cells (Lyons et al., 1990). 

The increase in size of anatase grains is a grain-growth transformation. 

---