Decomposition of solid solutions in Nb-W-Hf system

Using the method of X-ray analysis when studying samples of the system Nb-W-Hf over the cross sections Nb-(W:Hf)=2:1 and Nb-(W:Hf)=4:1 in the concentration range up to 10.7 mass% tungsten and up to 3.3 mass% hafnium the decomposition of β-ternary solid solution into two solid solutions (β1 and β2) depleted and enriched with alloying components respectively, has been detected for the first time. The process is observed in the alloys when total content of tungsten and hafnium constitutes 9.5 mass.%, over the cross section Nb-(W:Hf=4:1 and at 9.0% over the cross section Nb-(W:Hf=2:1)