The Reactions of Titanium and Niobium with Phosphorus

The 1070 K isothermal section of the phase diagram in the region of 0-0.67 molar fraction of P has been constructed by x-ray structure analysis in research on component interaction in the Ti ― Nb ― P system. Two series of continuous substitutional solid solutions are formed: (Ti, Nb₃P (Ti₃P) and (Ti, Nb)₇P₄ (Nb₇P₄), both between isostructural phosphides. The solid solutions based on the phosphides TiP (TiAs) and NbP (NbAs) attain the compositions Ti_0.8Nb_0.2P and Nb_0.9Ti_0.1P, while those based on the phosphides Nb₂P (Nb₂P), Ti₂P (Ti₂P), Ti₅P₃ (Yb₅Sb₃) attain the compositions Nb_1.9Ti_0.1P, Ti_1.9Nb_0.1P, Ti_4.6Nb_0.4P₃. Ternary phosphides are not formed in this system. The interactions in the Ti ― (V, Nb) ― P systems are examined.