Masters Theses

Abstract

"Chemical analyses were made on all three nitrides using oxidation, Kjeldahl, dissolution and gas evolution techniques, and the chemical formulae were calculated. They are as follows: Ti0•931N, Zr0•970N, and Hf0•792N.

The lattice constant of all the nitride samples was determined at 25°C. The Ti0•931N sample obtained from Union Carbide Company had a lattice parameter of 4.23986± 0.00007A0, while the sample from W. Germany, Ti1.0N in the as received condition had a lattice parameter of 4.24027 t 0.00003A0• A second lattice parameter determination was made on the W. German sample after being crushed and a value of 4.2416 ± 0.0001A0 was obtained. The deviation is attributed to composition in the first instance and to deformation in the second.

The lattice parameter values obtained for zirconium and hafnium nitrides at 25° c were 4.5118 ± 0.0001A0 and 4. 57560 ± 0.00005A0 respectively.

The thermal expansion coefficients for the various nitrides were calculated for the temperature interval from 10 to 6o0 c. The value for the Union Carbide TiN -6 0 -6 0 was 5. 71 x 10 / c, for the W. German sample 7 .05 x 10 / c, -6 '° and for the powdered W. German sample 6.81 x 10 1 C. respectively.

The densities were measured for the three nitrides iii and values of 4.975, 6.884, and 11.696 gm/cm3 were recorded for Ti0.931N, Zro.970N, and Hfo.792N, respectively.

The results obtained from the various chemical analyses suggested that the three compounds are ionic and that the metal ions exist in the trivalent state in the nitrides. This would require bound nitrogen to be present as N-3. The results of nitrogen analysis also reveal the presence of small amounts of free nitrogen trapped in the lattice. It would therefore appear that the bonding between the metal and the nitrogen is ionic rather than metallic.

All three nitrides were found to have defect structures and, in each case, to be defect in the metal ion. This defect structure was confirmed when the expression In' - nl was found to be greater than the propagated error, An'. The total number of defects, calculated for the nitrides, is as follows: TiN, 11.88%; ZrN, 7.20%; and HfN, 13.45%"-- Abstract, pp. ii - iii

Advisor(s)

Straumanis, Martin E., 1898-1973

Committee Member(s)

James, William Joseph
Frad, William A., 1909-1974
Lorey, G. Edwin

Department(s)

Materials Science and Engineering

Degree Name

M.S. in Metallurgical Engineering

Publisher

University of Missouri at Rolla

Publication Date

1964

Pagination

x, 106 pages

Note about bibliography

Includes bibliographical references (pages 103-105)

Rights

© 1964 Chester A. Faunce, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 1572

Print OCLC #

5957798

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