SELF-DIFFUSION IN BODY-CENTERED CUBIC ZIRCONIUM

Abstract

Self-diffusion coefficients of crystal-bar zirconium have been measured between 1500 °C and 1100 °C, using radioactive Zr95 as a tracer. The results may be represented by[Formula: see text]The pre-exponential factor is about three orders of magnitude smaller than that measured in most close-packed systems and the activation energy about one-half that anticipated from an empirical correlation with the melting point. The results, however, are similar to those of a few other recently studied body-centered cubic (BCC) systems, and agree quantitatively with work in the Soviet Union on zirconium. There is considerable evidence that the diffusion process occurs via vacant lattice sites.