Phase diagrams of the 4th group metals

In Fig. 5.18 on the other hand, binary systems of Ti, Zr, Hf are indicated in which complete mutual solubility in the solid state is observed (even if only in a limited range of temperature). Notice the peculiar behaviour of titanium which exhibits 

11 Compound-forming element 0 Phase diagram known no intermediate phases formed No information available 0 Questionable compound forming capability 

According to their effects on Ti alloying, elements may be subdivided in the following categories which represent an example not only of a structural, but also of an application-oriented classification  

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