title: Comparison of a modified Kjeldahl and a vacuum fusion technique for determination of nitrogen in tantalum alloys.
abstract: Results obtained for the determination of nitrogen in the tantalum alloys T-111 (Ta-8 W-2 Hf) and T-222 (Ta-10 W-2.5 Hf-0,1C) by Kjeldahl and vacuum fusion procedures are compared. Results obtained by each technique are shown for the determination of nitrogen m the MAB T-111 sample, two commercial T-111 samples and a commercial sample of T-222 alloy. In the 5-25 ppm range, the relative standard deviation was 3-9% by the Kjeldahl procedure and 4-8% by vacuum fusion. This is a measure of the homogeneity of the material as well as of the reproducibility of the results. The agreement of the results obtained by these two techniques increases confidence in the vacuum fusion results for nitrogen in tantalum.
authors.affiliation: Lewis Research Center, National Aeronautics and Space Administration, Cleveland, Ohio, U.S.A.
authors.forename: W F
authors.initials: WF
authors.lastname: Davis
authors.forename: J W
authors.initials: JW
authors.lastname: Graab
authors.forename: E J
authors.initials: EJ
authors.lastname: Merkle