Thermal reaction of SiC films with tungsten and tungsten–rhenium alloys
- 273 Downloads
Solid-state reactions between SiC films and W–xRe (x = 0, 5 and 25 at%) substrates on thermal annealing between 1673 K and 1873 K for various durations have been investigated. SiC coatings were deposited on metallic wires by hot filament chemical vapour deposition (HFCVD) from a gas mixture of tetramethylsilane (TMS) and hydrogen at 1373 K under normal pressure. The interface zones were characterized using scanning electron and optical microscopies, X-ray diffraction and electron microprobe microanalysis. All analyses reveal that SiC reacts with substrates. Various metal silicides and carbides were formed in layered reaction and the presence of these phases was confirmed by electron probe microanalysis. The effects of rhenium on the reactivity were established by the determination of growth kinetics deducted from the thicknesses of reaction zones as a function of annealing time. It has been found that an increase in the diffusion kinetics and activation energy with the quantity of rhenium in the tungsten wire.
KeywordsReaction Zone Rhenium Diffusion Couple Reaction Layer Atomic Composition
The authors wish to thank M. Lahaye (CeCaMA, Bordeaux) for his assistance in SEM and EPMA studies.
- 2.Space RI, Slack GA (1960) In: O’Connor JR, Smiltens J (eds) Silicon carbide, a high-temperature semiconductor. Pergamon, New YorkGoogle Scholar
- 3.Ryan CE (1969) Mater Res Bull S1:4Google Scholar
- 4.Price RJ (1977) Nucl Technol 320:35Google Scholar
- 5.Sasaki K, Sakuma E, Misawa S, Yoshida S, Gonda S (1984) Appl Phys Lett 72:45Google Scholar
- 10.van Loo FJJ, Smet FM, Rieck GD, Verspui G (1982) High Temp High Pres 14:25Google Scholar