TiB-TiC

The preceding analysis predicts that it will be difficult to form a TiB2/TiC/Ti composite using furnace infiltration temperatures near the Ti melting point. On the other hand, a different composite, a TiB/TiC/Ti material, has been successfully formed by reacting at 2000°C for times of 6 to 24 h. Under these conditions, molten Ti is in equilibrium with the... 

TiB and TiC solid phases. Although the solid layers described here still form, they tend to be thinner. Coupled with the additional processing time, the Ti flux is then high enough to form the TiB/TiC/Ti product. 

The non-stoichiometric, interstitial cubic compounds TiB, TiBg, TiC and TiN are very stable, strongly exothermic, and refractory. TiC is widely used in association with WC for tipping high-speed tools. 

One potential route around this problem is to infiltrate above the melting temperature of TiB, i.e., above 2190°C. In this case, the molten Ti will be in equilibrium with TiB2 and TiC, rather than TiB and TiC. The reaction conditions will then become similar to those in the Zr system. On cooling below 2190°C, though, the residual Ti in the composite should, at least thermodynamically, form TiB, according to a class II ternary reaction ... 

This reaction, though, will be kinetically slow because B must diffuse through a TiB product phase that will form on the TiB2. By performing the reaction in an inductively heated furnace in which these very high temperatures can be reached, a TiB2/TiC/Ti composite has been formed by the reaction of Ti with B4C [59],... 

Tia Tumor incidental histologic finding in 5% or less of tissue resected Tib Tumor incidental histologic finding in 5% or more of tissue resected Tic Tumor identified by needle biopsy (e.g., because of elevated PSA)... 

One of the peculiarities of the natural diamond is a considerably lower content of admixtures Ni, Mn, oth. as compared to the synthetic diamond. It is this feature that determines its raised resistance to the action of high temperature in the combustion wave. Figure 3 shows the dependencies of the recuperated synthetic and natural diamond strength on the mass proportion of the charge layers mi/m2 with diamond concentration equal to 25 % vol. on the example of the bi-layered composite with the ceramic binder (Ti,Mo)Ca. The strength of diamond grains is also affected by mi/m is the composites with the binder of NiAl, TiB+Ti, TiC-l-TiAl, TiB2+Si. 

Human ceruloplasmin consists of a single polypeptide chain with a MW of 132 kDa folded in six cupredoxin domains arranged in a triangular array. Each domain comprises a p-barrel, constructed in a Greek key motif, typical for the cupredoxins. Three of the six copper ions are bound to T1 sites present in domains 2, 4, and 6, whereas the other three copper ions form a trinuclear cluster, bound at the interface between domains 1 and 6 (Fig. 10). The spatial relation between the trinuclear center and the nearest T1 site (A, in domain 6) closely resembles that found in AO and was taken to further support the proposal that hCp has an oxidase function. The three T1 sites are separated from each other by a distance of 1.8 nm, a distance that might still allow for internal ET at reasonable rates and could also increase the probability for electron uptake. The coordination sphere of the T1 site in domain 4 (TIB) is identical with that of domain 6 (TIA). The third type 1 center (TIC), however. 

The 3D structure of hCp further resolved five disulfide bridges distributed evenly throughout the protein in domains 1-5. All five disulfides are near the bottom of a 3-barrel, and in two domains the Tl copper centers (TIB and TIC) are placed at the opposite end of the barrel. The only domain lacking a disulfide is domain 6, which contains TIA and the trinuclear copper centers. 

Electronic couphngs between pairs of the three different T1 centers have also been calculated. These centers are connected pairwise by 13 covalent and 2 hydrogen bonds, resulting in an electronic decay coupling factor of 1.7 x lO. However, in spite of this relatively short distance, intramolecular ET between these sites is not expected. The high-potential TIC is, as mentioned above, most likely in the reduced state even in the resting (as isolated) enzyme and thus not involved in ET at all. The driving force for TIA to TIB ET is very low or even... 

Although rather unreactive at ordinary temperatures, titanium combines directly with most non-metals, for example, hydrogen, the halogens, oxygen, nitrogen, carbon, boron, silicon, and sulfur, at elevated temperatures. The resulting nitride, TiN, carbide, TiC and borides, TiB and TiB2, are interstitial compounds which are very stable, hard and refractory. 

Intillration composite SiC-TiC/TiN-TiB, High-performance brake disks, components for tribology... 

When zirconium silicate (ZrSi04) or a mixture of Z1O3 and SiOj is reacted with aluminum in the presence of aluminum oxide and then rdieated, zirconium silicide (ZrSi ) becomes the major product. Titanium dioxide (TiOs) and boron (111) oxide (BgO,) with aluminum similarly form titanium boride (TiBs). If the reduction of the oxides such as TiOg or Si02 with aluminum is performed in the presence of carbon black, the carbides TiC and SiC are formed embedded in aluminum oxide. This subject is also treated in a British patent titled Autothermic Fired Ceramics. ... 

Therefore active bases to heterogeneous nucleation for aluminum are particles which have high melting point i.e. TiC, TiN, TiB, TiB2, AIB2 i AlsTi (Tab.l) (Easton Stjohn, 1999a,... 

Similar tendencies were established from calculations of clusters simulating O adsorption at the different adsorption centres in TiC, TiN and TiB surfaces (Table 8.2). For all the systems considered, the Ti-O bond populations are much less than for X-O bonds. The population of Ti-O bonds in TiB (0.012) is less than that of Ti-O bonds in TiC (0.103) and TiN (0.125), while the ratio of (O-X) to (O-Ti) populations equals 7.3 for TiN, 7.81 for TiC, and 35.7 for TiB surfaces, i.e., this ratio is maximal for the boride surface. 

Specimen Composition (at %) Molar fraction of TiB , TiB2/ (TiC -i TiB2) Heat load of crack initiation (kW/cm ) Thermal diffusivity at room temperature (10- mVs)... 

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