hafnium carbide

hafnium carbide

[′haf·nē·əm ′kär‚bīd]
(inorganic chemistry)
HfC Gray powder, melting at 3887°C; used in the control rods of nuclear reactors.
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References in periodicals archive ?
Hafnium Carbide and diboride are ceramics with ultra-high melting temperatures representing the upper end of refractory materials.
Abstract Hafnium carbide coatings with different carbon contents were synthesized in Ar-[C.sub.2][H.sub.2] mixture by reactive magnetron sputtering.
Keywords Hafnium carbide, Hard coatings, Microstructure, Mechanical properties, Magnetron sputtering
Hafnium carbide coating has high hardness, excellent wear resistance, good resistance to corrosion, and low thermal conductivity, which are ideal characteristics for use in high-temperature applications.
In this article, a series of hafnium carbide coatings with different carbon contents were synthesized by reactive magnetron sputtering, and the effects of different [C.sub.2][H.sub.2] partial pressures on the composition, phase, microstructure, and mechanical properties of the coatings were investigated.
A series of hafnium carbide coatings with different carbon contents were synthesized by reactive magnetron sputtering on ANELVA SPC-350 multi-target magnetron sputtering system.
The phase constituting hafnium carbide coatings was determined by X-ray diffraction (XRD) on the Dmax-2550/PC diffractor with Cu-[K.sub.[alpha]] excitation radiation.
The composition of hafnium carbide coatings acquired at different [C.sub.2][H.sub.2] partial pressures analyzed by EDX is listed in Table 1.
Table 1: Composition of hafnium carbide coatings at different [C.sub.2][H.sub.2] partial pres Sample 1 2 [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (x 5 10 [10.sup.-3] pa) [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (%) 0.83 1.67 C (at.%) 22.9 34.5 Hf (at.%) 77.1 65.5 Sample 3 4 [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (x 15 20 [10.sup.-3] pa) [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (%) 2.50 3.33 C (at.%) 48.5 56.9 Hf (at.%) 51.5 43.1 Sample 5 6 [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (x 25 30 [10.sup.-3] pa) [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] (%) 4.17 5.00 C (at.%) 71.0 85.1 Hf (at.%) 29.0 14.9 The XRD patterns of hafnium carbide coatings with different carbon contents are shown in Fig.
Hafnium carbide coatings can be synthesized by reactive magnetron sputtering in Ar and [C.sub.2][H.sub.2] mixture conveniently.
Examples include 20-vol% indium tin oxide in PMMA, 20- to 80-vol% hafnium carbide fillers in PMMA, and 15- and 20-vol% copper in PMMA and PVA.
Such ceramics are difficult to mold into body-friendly shapes, since they are made of very hard ceramics such as boron carbide, zirconium carbide, hafnium carbide, titanium carbide, or zirconium diboride.