Effect of oxygen on microstructure and mechanical properties of niobium

The effect of oxygen on microstructure and mechanical properties of niobium has been investigated. Niobium samples containing 50–800 wt. ppm oxygen have been prepared by absorption and diffusion techniques. The samples were characterised with respect to chemical composition, microstructure and mechanical properties. Niobium containing up to 800 wt. ppm of oxygen exhibited essentially single phase microstructure with no precipitates. The hardness and strength increase with increase in oxygen content. The increase in strength is marginal up to 400 wt .ppm oxygen and significant from 400 to 800 wt .ppm oxygen.