Effect of phosphorus on the mechanical behavior of a Zr–Nb alloy

The flow stress of Zr–1.0Nb increased with the addition of 20 ppm phosphorous and the activation volume decreased with the addition of 300 ppm phosphorous at room temperature. The rate-controlling mechanism of the deformation of Zr–Nb–P is thought to be the dislocation-solute interaction in which the segregation of alloying elements affects the activation length. Less effective strengthening of phosphorous in Zr–Nb compared to sulphur was explained by a smaller electrostatic interaction between phosphorous atoms and dislocations.