Effect of high pressure on the formation of ordered phases in Ta-C systems

Journal Article · Fri Mar 01 04:00:00 EST 1985 · Inorg. Mater. (Engl. Transl.); (United States)

OSTI ID:6461019

Markhasev, B I; Dzhamarov, S S; Geshko, E I; Klyugvant, V V; Pilipovskii, Y L; Shamatov, Y M

This paper considers the effect of pressure on the completion of the transformations TaC /SUB x/ Ta/sub 4/C/sub 3/ and TaC /SUB x/ Ta/sub 2/C. The data show that in the samples with C/Ta = 0.68 and 0.71, the applied pressure substantially increases the diffraction peak heights of the ordered phases, Ta/sub 4/C/sub 3/ and Ta/sub 2/C. In samples with C/Ta = 0.76, high pressure does not generally increase the intensities of the diffracted peaks of Ta/sub 4/C/sub 3/ and Ta/sub 2/C, however the equilibrium between them is displaced to the side of increased Ta/sub 2/C content. In one of the samples a complete disappearance of the disordered TaC /SUB x/ is not observed. It is concluded that high pressure ( about7GPa) promotes the transition of nonstoichiometric TaC /SUB x/ into ordered Ta/sub 4/C/sub 3/ and Ta/sub 2/C as well as broadens the existence region of the latter. A complete transformation of TaC /SUB x/ into the ordered phase does not occur even at pressures up to about 9 GPa.

• Research Organization: Inst. of Problems in Materials Science, Academy of Sciences of the Ukranian SSR, Chernov State Univ.,
• OSTI ID: 6461019
• Journal Information: Inorg. Mater. (Engl. Transl.); (United States), Journal Name: Inorg. Mater. (Engl. Transl.); (United States) Vol. 20:10; ISSN INOMA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
CARBIDES
CARBON COMPOUNDS
CRYSTAL STRUCTURE
CRYSTAL-PHASE TRANSFORMATIONS
EQUILIBRIUM
PHASE STUDIES
PHASE TRANSFORMATIONS
PRESSURE EFFECTS
REFRACTORY METAL COMPOUNDS
TANTALUM CARBIDES
TANTALUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS