Diffusion of ⁵⁹Fe in single-crystal α-Zr

Abstract

Diffusion coefficients D of ⁵⁹Fe have been measured in single crystal α-Zr in the range 765-1193 K (in directions both parallel (D_∥) and perpendicular (D_⊥) to the c axis) and in a polycrystalline Zr–0•28 at.% Fe alloy, in the range 733–1070 K. The single-crystal results show that D_∥/D_⊥ has values between 2•2 and 5•9, for T < 1143K, and about 1•22, for 1154–1193 K; the persistence of the anisotropy beyond the nominal α-phase range (T < 1136 K) is surprising. The a-phase D_∥ results show a complex temperature dependence which appears to parallel, to a notable degree, that shown by recent measurements of α-Zr self-diffusion. The D values for the alloy are about ten times less than the corresponding (average) single-crystal results.