Interfacial reactions in layered composites of Nb-A12O3AND Nb (1% Zr)-Al2O3 in high-temperature annealing

Results of a study of the interaction in layered composites of niobium and a niobium alloy (1% Zr) with a pure-corundum ceramics in vacuum annealing in the range of 1770–2070 K are presented. Cylindrical specimens were fabricated by plasma deposition of the ceramics and high-temperature isostatic pressing of the packet through a metal shell. The microstructure, the phase composition of the contacting layers, and the removal of mass from the contact zones on end faces of the specimens in direct contact with the vacuum are described. The data obtained are used to make conclusions on the causes of the differences in the behavior of specimens with pure niobium and with the niobium alloy.