Reactions of niobium and tungsten with phosphorus

X-ray diffraction methods have been applied to the component interaction in the Nb-W-P system in the region of 0–0.67 molar parts of P. An isothermal section of the phase diagram at 1070 K has been constructed. No ternary compounds are formed in the system. The phosphide Nb₃P (structure of Ti₃P type) dissolves tungsten to the limiting composition N_1.8W_1.2P (a = 1.0006(6) nm, c = 0.5073(2) nm). The solubility of tungsten in other niobium phosphides does not exceed 0.05 molar fraction. __________ Translated from Poroshkovaya Metallurgiya, Nos. 7–8(450), pp. 76–80, July–August, 2006.