Iron dendrites formation

The occurrence of radial type symmetries rather than more restricted ones necessitates a spatial freedom in all relevant directions. Thus, for example, the copper formation in Figure 2-10a has a tendency to form cylindrically symmetric structures. On the other hand, the solidified iron dendrites obtained from iron-copper alloys, after dissolving away the copper, display bilateral symmetry in Figure 2-lOb. 

The covering is energetically justified by a film of carbon of a surface bubble, for conducts to decrease of superficial energy of iron [6], On formation of structure melted of pig-iron the large influence is rendered by completeness of dissolution of the deformed graphite, rate of the subsequent cooling melted of sites, branching dendrites superfluous austenite. 

For instance, the nickel-iron battery, invented almost at the same time (Edison, 1901) as the nickel-cadmium battery, has a poor charge efficiency, which causes excessive heating and hydrogen release. Another example is nickel-zinc technology, for which further study seems necessary, because it is subject to the formation of dendrites which limit its lifetime. 

Surface Finishes. Galvanized coatings are commonly characterized by surface spangles. In cross section, an Fe2Al (Zn) inhibition layer develops first, preventing any iron-zinc intermetallic phase formation. The overlay layer is made up of dendrites of pure zinc (t ) phase and appears as a poly-crystaUine structure. The three surface finishes commonly produced are ... 

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