Solidification equiaxed zone

Figure 4.5 Section through a solidification ingot showing the various solidification zones. The equiaxed zone forms near the mold walls. In the interior is the columnar zone, where crystal growth is in the direction of heat flow. (After Lalena and Cleary, 2005. Copyright John Wiley Sons, Inc. Reproduced with permission.)...

Solidification. When the ingot or casting solidifies, there are three main possible microstructures that form (see Figure 7.5). We will describe here only the final structures the thermodynamics of the liquid-solid phase transformation have been described previously in Chapter 2. The outside layer of the ingot is called the chill zone and consists of a thin layer of equiaxed crystals with random orientation. 

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