Investigation of 100-hour aging of niobium composite reinforced with monocrystalline fibers α-al2o3

The influence of 100-hour aging at 1350 °C on the «matrix-fiber» interphase interaction, the matrix structure and high-temperature strength of a niobium composite reinforced with monocrystalline fibers α-Al2O3 has been investigated. The chemical interaction in the Nb-αAl2O3 interface did not found out both in starting samples after pressing and in samples after 100-hour aging. This assumes the absence of chemical bonding and the existence of mechanical frictional bond, according to Bowman. Simultaneously, a process of mutual diffusion elements of the matrix and fiber in the Nb-αAl2O3 interface after 100-hours of aging was studied. An increase in strength of the composite material during aging was observed. This indicates an increase in the frictional bonding (mechanical frictional bond) and / or the formation of «new» bond that at this stage does not lead to fiber degradation. The numerical values of contribution of «new» bond to strength of the composite material were not established.