Solubility of the elements in titanium

Summary

• 1. The solubility of the elements in titanium follows a pattern similar to that characterizing the solubility of the elements in other metals, such as iron, nickel, and chromium.

• 2. The formation, or non-formation, of solid solutions in binary titanium systems is associated with the relative similarity, or dissimilarity, in the properties of the elements, as indicated by Mendeleev's periodic system.

• 3. Metals which are titanium analogs (zirconium and hafnium), or are closely situated in Groups V and VI, and which differ little in atomic diameter and have isomorphous structures, are able to form continuous solid solutions with titanium.

• 4. The metals that are the most removed from titanium-elements of Groups I and II, and the Group VIII-have a lower tendency to form solid solutions. Most of the Group I and II metals do not interact with titanium in the liquid or solid state, and do not form solid solutions. Group VIII metals form only limited solid solutions.

• 5. Elements of low atomic diameter (H, C, N, O) are able to form solid solutions of the interstitial type in low concentration, and to form also interstitial compounds: hydrides, carbides, nitrides, and oxides of titanium.

• 6. The regularities established for the solubilities of the elements in titanium can be applied to the examination of the solubilities of the elements in the titanium analogs zirconium and hafnium. This will facilitate the general consideration of the phase diagrams of zirconium and hafnium systems, the great majority of which have not been studied.