Effect of titanium on stabilization of niobium suboxides

The effect of titanium on the oxidizability of niobium was previously studied and a concept put forth that the increased heat resistance occurs due to stabilization of the suboxides at temperature above 700 deg C. In this work, alloys of niobiura with oxygen (from 1 to 43 at.% oxygen) were studied in which 2 at.% titanium had been added. Alloying of niobiura with titanium leads to an increase in the maximum content in the solid solution from 6 to 8 at.% after quenching. Oxygen content in solid solutions after annealing at 500 and 700 deg C was 7 and 6 at.%, respectively. At 500 deg C, Nb/sub 2/O decomposes from the solid solution as an excess phase during annealing and, at 700 deg C and above, NbO is the decomposed excess phase. After annealing at 300 deg C there was noted a significant widening of niobium lines on noutronograms which may be the result of decomposition of a supersaturated solid solution with the formation of the suboxide of the type Nb/sub 6/O. This anomalous behavior of oxygen in niobium with 2 at.% Ti should render an effect on the mechanical properties of alloys of niobium with titanium and an increasedmore » oxygen content. (JPRS)« less