Titanium diboride fiber

Another candidate material for high temperature fiber is titanium diboride. It has a melting point of around 3000°C. Diefendorf and Mazlout (1994) used a gas mixture of titanium tetrachloride boron trichloride, hydrogen, and hydrochloride to make titanium diboride fibers by chemical vapor deposition (CVD) in a cold wall reactor at atmospheric pressure. 

Fibers of titanium diboride can be prepared by reaction (a) at 400°C in an electrical discharge. Adherent layers of certain metal borides on metal substrate surfaces are obtained by thermal decomposition of metal (Mo, W, Nb, Ta) halides and BBr3 on a metallic substrate using a solar furnace or induction heating ... 

Several fiber types have been mentioned so far, and several other types have been neglected that have been worked on over the past few years. Some of those not discussed may become important fibers for reinforcement in the years ahead. To date though, they have not been available in sufficient quantity for thorough evaluation in composite specimens. Included in this group are boron carbide, spinel, polycrystalline alumina and silica, titanium diboride, and miscellaneous silicides and intermetallics. Ten years from now as we look back on the 70s we no doubt will have an entirely different view of some of these materials. 

Aveston, J., Cooper, G.A., Kelly, A. (1971), Single and multiple fracture , in The Properties of Fiber Composites, IPC Science Technology Press, Guildford, UK, 15-22 Bahr, H.A., Weiss, H.J., Maschke, H.G., Meissner, F. (1988), Multiple crack propagation in strip caused by thermal shock , Theor. Appl. Fract. Mech., 10, 219-226. Bannister, M.K., Swain, M.V. (1990), Thermal shock of a titanium diboride based composite , Ceram. Int., 16, 77-83... 

Titania. See Titania-silica, Titanium oxide Titanium alkoxide, 226 condensation catalyst, 226, 227 Titanium diboride, 289 Titanium oxide, 254, 257, 283, 285, 286, 288-290, 370 aerogel, 502 crystallization, 780 fiber, 865... 

Ceramic Matrix Composites (CMC) performed by a hybrid process is described in this paper. This process is based on (i) the chemical vapor deposition of carbon interphase on the fiber surface, (ii) the introduction of mineral powders inside the multidirectional continuous fiber preform and (Hi) the densification of the matrix by Spark Plasma Sintering (SPS). To prevent carbon fibers and interphase from oxidation in service, a self-healing matrix made of silicon nitride and titanium diboride was processed. A thermal treatment of 3 minutes at 1500 C allows to fully consolidate by SPS the composite without fiber degradation. The ceramic matrix composites obtained have an ultimate bending stress at room temperature around 300 MPa and show a self-healing behaviour in oxidizing conditions. 

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