Bulk Diffusion of Homovalent Non-Magnetic Atomic Probes of Titanium and Zirconium in Tungsten Single Crystals

The bulk diffusion of homovalent non-magnetic atomic probes (APs) from the IVB group of the periodic table of elements (PTE) – Ti and Zr in tungsten single crystals was investigated by sec-tioning, using secondary ion mass spectrometry (SIMS). The Arrhenius dependences had the fol-lowing parameters: DWTi - (D0)WTi = (3.00.4 ) x 10-4 m2s-1, enthalpy QWTi = (576 ± 9) kJ/mole; DWZr - (D0)WZr = (2.3  0.6) x 10-4 m2s-1, QWZr = (561 9) kJ/mole. The measured parameters (D0,Q)WTi,Zr of diffusion of Ti and Zr atomic probes (APs) in W are in accord with the empirical correlation: the diffusion coefficients of the substitutional APs coincide with the self-diffusion coefficients in W at (Tm)W – its melting temperature. Enthalpies QWTi,Zr,Hf of the volume diffusion of homovalent non-magnetic APs of the IVB group of periodic table of elements (PTE) - Ti, Zr and Hf increase with the decrease of relaxation volumes of the complexes «vacancy-IVBAP» in W lattice. The energies (E)WvacIVBAP of elastic relaxation of the complexes «vacancy-IVBAP» in W lattice were estimated. Electron contributions EDN to the energies EWvacIVBAP of interaction of the point defects in complexes «vacancy-IVBAP» increase relative to value EWvacIIIBAP of interac-tion of the point defects in complexes «vacancy-IIIBAP» with the growth of d-electrons number in comparison with the complexes «vacancy-IIIBAP».