# What is solid-solid transformation?

I found solid-solid transformation on Wikipedia Please tell me what it is? It's present in types of phase transition in Wikipedia.

• Ice has a dozen different states, my guess is that it refers to something like that Jan 21 '14 at 11:34

So if you take $\alpha$-iron at room temperature and heat it to above 912C it will transform to the $\gamma$-iron structure. The conversion between the $\alpha$ and $\gamma$ structures is a first order phase transition (known as the austentitic transition) and it occurs in the solid state. Hence it is an example of a solid state phase transition.