Titanium additives

Research has focused on V—Cr—Ti—Si alloys, having 0.15 wt % Cr, 0—20% Ti, and less than 1% Si. Titanium additions above 3 wt % drastically reduce the magnitude of radiation-induced sweUing. The alloy of greatest interest is V—5Ti—5Cr (31). 

The Krupp work had shown interesting improvements in acid resistance resulting from molybdenum and copper additions, and the use of 2-3% Mo for more difficult acid conditions was soon established. Other early additions were made to overcome susceptibility to intercrystalline corrosion, culminating in the general use, by the early thirties, of titanium additions for carbide stabilisation, followed shortly after by the alternative use of niobium. 

T.T.S curves as those in Fig. 3.21 can be developed for material cooled very rapidly following solution treatment but the C curve range is a OO-550°C and the nose is at very short times. Freedom from sensitisation in welding can be obtained by ensuring extremely low carbon (and nitrogen) but such levels are not commercially feasible. Stabilisation by niobium and titarium is feasible, but higher ratios are needed than with austenitic steels. With most of the super ferritic group a combination of a practical low carbon level and titanium addition is used. 

Figure 10. Effect of titanium addition on the dynamic mechanical behavior of TEOS-PTMO materials (PTMO MW=2000), (a) storage modulus and (b) tan8.

Thus, in summary, the composition can be divided into propellant, emitter and additives. The propellant is invariably gunpowder, whilst the emitter might be carbon, steel, iron, aluminium, magnesium/ aluminium alloy or even titanium. Additives are often used to promote the visual effects and to cheapen the composition. 

C-M bond addition, for C-C bond formation, 10, 403-491 iridium additions, 10, 456 nickel additions, 10, 463 niobium additions, 10, 427 osmium additions, 10, 445 palladium additions, 10, 468 rhodium additions, 10, 455 ruthenium additions, 10, 444 Sc and Y additions, 10, 405 tantalum additions, 10, 429 titanium additions, 10, 421 vanadium additions, 10, 426 zirconium additions, 10, 424 Carbon-oxygen bond formation via alkyne hydration, 10, 678 for aryl and alkenyl ethers, 10, 650 via cobalt-mediated propargylic etherification, 10, 665 Cu-mediated, with borons, 9, 219 cycloetherification, 10, 673 etherification, 10, 669, 10, 685 via hydro- and alkylative alkoxylation, 10, 683 via inter- andd intramolecular hydroalkoxylation, 10, 672 via metal vinylidenes, 10, 676 via SnI and S Z processes, 10, 684 via transition metal rc-arene complexes, 10, 685 via transition metal-mediated etherification, overview,... 

Figure 6.15 Deboronation and titanium addition of B-containing zeolite p through hydrolysis or alcoholysis. Reproduced with permission from [35], Copyright (1994) Elsevier...

The recent examination of titanium containing Au/SBA-15 catalysts was carried out comparing titanium incorporated hydrothermally and by posts)mthesis grafting using titanium (IV) oxyacetylacetonate monohydrate [84]. Titanium addition by grafting resulted in more active and selective catalysts, though overall the catalysts had lower activity relative to others prepared using mesoporous titano-silicates. This is in direct contrast to the results found for Au/Ti-MCM-41... 

Table V shows the effect of Ti, Zr, and Sn addition when excess antimony was present. Although each Increased catalyst activity, the effect was much smaller than for the USb. M Oy compositions. Titanium addition about doubled the relative activity compared to the standard uranium-antimony oxide catalyst, while Zr and Sn addition had a smaller effect. The poor selectivity of the Distillers-type catalyst. No. 9, is attributed to the presence of USbO. ...

The important forms of titanium are its dioxide, the tetrachloride compounds, and the metal. The metal and its alloys are used in applications such as the space industry, tubings and surgical implants or prostheses, where strength, lightness and resistance to corrosion are desirable. Titanium additions to chromium-nickel steel are transformed during production into titanium carbide inclusions with increased strength. Titanium tetrachloride is an intermediate in titanium production, and is used by the military for generating smokescreens. 

Figure 14. Nitrogen concentration in diamond versus the cobalt content of iron + cobalt solvent. The diamonds were grown with 1.5 weight-% titanium addition using (a) high-purity graphite and (b) synthetic diamond powder [67].

Niobium additions, it was stated, behaved similarly, and only heat treatment, as described previously, was effective in conferring immunity to nitric acid. It was reported [37], however, that columbium additions (8x C + N content), but not titanium additions, minimize the observed intergranular corrosion of welds exposed to boiling 65% HNO3. This behavior may be explained by the observed marked reactivity of titanium carbides, but not niobium carbides, with HNO3 along grain boundaries where such carbides are concentrated [38]. 

Type 321 is similar to 304 but with titanium addition five times the carbon content that reduces carbide precipitation during welding and in 425-815 C service. It has excellent corrosion resistance toward most chemicals and oxidation resistance up to SIS C. Aircraft exhaust manifolds, boiler shells, process equipment, expansion joints, cabin heaters, fire walls, flexible couplings, pressure vessels. 

Alloy G is intended for use in the as-welded condition, even under the circumstances of mulfipass welding. The Columbian addition provides better resistance in highly oxidizing environments than does titanium additions. Because of fhe nickel base, the alloy is resistant to chloride-induced stress corrosion cracking. The 2% copper addition improves the corrosion resistance of the alloy in reducing acids, such as sulfuric and phosphoric. Alloy G will resist combinations of sulfuric acid and halides. 

Ti-15Mo-5Zr has high corrosion resistance to reducing atmospheres. It has better corrosion resistance in boiling hydrochloric acid or sulfuric add solutions than commerdally piu e titanium. Additionally, Ti-15Mo-5Zr has higher erosion resistance compared to Ti-6A1-4V or other P titanium alloys. 

Intergranular Corrosion Resistance AL 29-4C contains a deliberate titanium addition to stabilize the carbon and nitrogen. AL 29-4C is resistant to intergranular corrosion as determined by the copper-copper sulfate-sulfuric acid tests detailed in ASTM Specification A 763, Practices Y and Z. 

Precipitation hardening steels These are steels with high toughness, high strength and having optimum creep properties. Aluminum, molybdenum, copper and titanium additions are made for intermetallic strengthening. 

Titanium additions have been shown to improve ductility in NisSi (Takasugi et al., 1990). To obtain single-phase alloys, these compounds have to be made with the nickel concentration above 75%. Titanium additions as great as 9% provide little improvement in ductility as long as the nickel concentration is below 78%. If the nickel concentration is allowed to increase to 80%, an improvement in ductility is measured, as shown in Figure 6. These data were obtained from tensile tests run in room-temperature air. This figure... 

Pan] Panseri, C, Guastalla, B., Investigations on the Permanent Modifieation of Euteetie Aluminium-Silicon Alloys. I.-Influence of Titanium Additions as the Third Component (in Italian), 10(5), 202-227 (1941) (Phase Diagram, Experimental, Review, 161)... 

Zhu] Zhu, S.M., Sakamoto K, Tamura M, Iwasaki K, Effects of Titanium Addition on the Micro-stmcture and Mechanical Behavior of Iron Aluminide of Fe3Al , Mater. Trans. JIM, 42, 484-490 (2001) (Crystal Stmcture, Experimental, Meehan. Prop., 22)... 

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