Dissolution kinetics of small amounts of oxygen in tantalum alloy T-111 and internal oxide displacement reactions during annealing

Journal Article · Fri Oct 01 04:00:00 EDT 1976 · Oxid. Met.; (United States)

DOI:https://doi.org/10.1007/BF00612028· OSTI ID:7218845

Stecura, S

Oxygen was added to T-111 (Ta--8W--2Hf, wt. %) at 820 and 990/sup 0/C at an oxygen pressure of about 3 x 10/sup -4/ Torr (4 x 10/sup -2/ N/m/sup 2/). The technique employed permitted predetermined and reproducible doping of T-111 up to 3.0 at. % oxygen. Based on the temperature dependence of the doping reaction, it is concluded that the initial rates of oxygen pickup are probably controlled by solution of oxygen into the T-111 lattice. Although hafnium oxides are more stable than those of tantalum or tungsten, analyses of extracted residues indicate that the latter oxides predominate in the as-doped specimens, presumably because of the higher concentrations of tantalum and tungsten in the alloy. However, high-temperature annealing promotes gettering of dissolved oxygen and of other oxides to form hafnium oxides. Small amounts of tantalum and tungsten oxides were still present after high-temperature annealing. Tungsten oxide (WO/sub 3/) volatilizes slightly from the surface of T-111 at 990/sup 0/C. The vaporization of WO/sub 3/ has no apparent affect on the doping reaction.

• Research Organization: Lewis Research Center, Cleveland
• OSTI ID: 7218845
• Journal Information: Oxid. Met.; (United States), Journal Name: Oxid. Met.; (United States) Vol. 10:5; ISSN OXMEA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
CHEMICAL REACTIONS
CRYSTAL DOPING
HAFNIUM ALLOYS
HIGH TEMPERATURE
OXIDATION
TANTALUM ALLOYS
TANTALUM BASE ALLOYS
TUNGSTEN ALLOYS