Titanium molybdenum

Peripheral pitting and etching associated with the low current densities arising outside the main machining zone occur when higher current densities of 45-75 A/cm are appHed. This is a recurrent difficulty when high alloy, particularly those containing about 6% molybdenum, titanium alloys are electrochemicaHy machined. 

Another anomalous property of some nickel—iron aHoys, which are caHed constant-modulus aHoys, is a positive thermoelastic coefficient which occurs in aHoys having 27—43 wt % nickel. The elastic moduH in these aHoys increase with temperature. UsuaHy, and with additions of chromium, molybdenum, titanium, or aluminum, the constant-modulus aHoys are used in precision weighing machines, measuring devices, and osciHating mechanisms (see Weighing AND proportioning). 

Specific fabrication temperatures are given by Czarnecki etalJ for various forming processes, including roll forming, hydropressing, joggle and die forming on molybdenum-titanium alloy sheet. 

Water The corrosion resistance of pure niobium in water and steam at elevated temperatures is not sufficient to allow its use as a canning material in water-cooled nuclear reactors. Alloys of niobium with molybdenum, titanium, vanadium and zirconium however have improved resistance and have possibilities in this application. Whilst the Nb-lOTi-lOMo alloy offers... 

The oxidation rate of niobium in air from 800°C to above 1000°C can be decreased by alloying e.g. with hafnium, zirconium, tungsten, molybdenum, titanium or tantalum . However, the preferred fabricable alloys still require further protection by coating . Ion implantation improves thermal oxidation resistance of niobium in oxygen below 500°C . 

Cihal, etal presented early data on the effects of chromium, nickel, molybdenum, titanium, niobium and silicon on the passive behaviour of stainless steel. 

This process, originally designated as RSR (rapid solidification rate), was developed by Pratt and Whitney Aircraft Group and first operated in the late 1975 for the production of rapidly solidified nickel-base superalloy powders.[185][186] The major objective of the process is to achieve extremely high cooling rates in the atomized droplets via convective cooling in helium gas jets (dynamic helium quenching effects). Over the past decade, this technique has also been applied to the production of specialty aluminum alloy, steel, copper alloy, beryllium alloy, molybdenum, titanium alloy and sili-cide powders. The reactive metals (molybdenum and titanium) and... 

The solvent process involves treating phthalonitrile with any one of a number of copper salts in the presence of a solvent at 120 to 220°C [10]. Copper(I)chloride is most important. The list of suitable solvents is headed by those with a boiling point above 180°C, such as trichlorobenzene, nitrobenzene, naphthalene, and kerosene. A metallic catalyst such as molybdenum oxide or ammonium molybdate may be added to enhance the yield, to shorten the reaction time, and to reduce the necessary temperature. Other suitable catalysts are carbonyl compounds of molybdenum, titanium, or iron. The process may be accelerated by adding ammonia, urea, or tertiary organic bases such as pyridine or quinoline. As a result of improved temperature maintenance and better reaction control, the solvent method affords yields of 95% and more, even on a commercial scale. There is a certain disadvantage to the fact that the solvent reaction requires considerably more time than dry methods. 

Uranium reacts with most nonmetallic elements to form a variety of compounds, all of which are radioactive. It reacts with hot water and dissolves in acids, but not in alkalis (bases). Uranium is unique in that it can form solid solutions with other metals, such as molybdenum, titanium, zirconium, and niobium. 

Tri-n-octylphosphine oxide (TOPO) has been the most popular phosphine oxide to be used as an extractant for the determination of iron, uranium, plutonium, molybdenum, titanium and thorium among other metals.43 44... 

VII.l INTRODUCTION In the previous chapters the discussions were restricted to those cations and anions which occur most often in ordinary samples. Having studied the reactions, separation, and identification of those ions, the student should now concentrate on the so-called rarer elements. Many of these, like tungsten, molybdenum, titanium, vanadium, and beryllium, have important industrial applications. 

Iron-chromium alloys, free from carbon, may be prepared from chromite by the alumino-thermic method. From a study of the cooling-and freezing-point curves it has been suggested that a compound, Cr Fe, exists, but this is questioned by Janecke, who studied the iron-chromium system by means of fusion curves and by the microscopic study of polished sections of various alloys between the limits 10 Fe 90 Cr and 90 Fe 10 Cr, and came to the conclusion that the system consists of a single eutectic which can form mixed crystals with either component. The eutectic contains 75 per cent, of chromium and melts at 1320° C. The addition of chromium to iron increases the readiness of attack by hydrochloric and sulphuric acids, but towards concentrated nitric acid the alloys are rendered passive. They remain bright in air and in water. The presence of carbon increases the resistance to acids and renders them very hard if carbon-free, they are softer than cast iron. All the alloys up to 80 per cent, chromium are magnetic. Molybdenum, titanium, vanadium, and tungsten improve the mechanical properties and increase the resistance to acids. 

Oxidation-reduction reactions are an important component of chemical analysis. Potassium perman-gante and cerium (IV) solutions can be used as strong oxidizing agents in the analysis of iron, tin, peroxide, vanadium, molybdenum, titanium, and uranium. Potassium dichromate is an oxidizing agent used in the analysis of organic materials in water and wastewater. 

Discaloy [Westinghouse], TM for an austenitic iron-base alloy containing nickel, chromium, and relatively small proportions of molybdenum, titanium, silicon, and manganese. This alloy is precipitation-hardened and was developed primarily to meet the need for improved gas-turbine disks, one of the most critical components of jet engines. 

Iron-molybdenum-titanium oxides were prepared via the sol-gel method. Either (NH4)6Mo7024 4H20, and ferric nitrate (FeN), Fe(N03)3-9H20, or FeCb and MoOCL were used as precursors together with Ti-isopropoxide. These solids were characterised by chemical analysis and N2 adsorption. The sol-gel samples developed higher surface areas (c.a. 100 m g ), except for the sol-gel solid prepared with Fe and Mo chlorides as precursors, than those prepared by impregnation. 

The aim of this work is to develop new Fe-Mo containing mixed oxides highly dispersed in a titania matrix, prepared by the sol-gel method, and to compare these materials to those of iron molybdate prepared by conventional methods (i.e. impregnation). Here, we report the preparation of sol-gel derived iron molybdenum titanium mixed oxides. The bulk composition and the textural properties of these materials are investigated by elemental chemical analysis and N2 adsorption, respectively. 

Mittasch and Schneider. The first patent for the synthesis of methanol was granted in Germany to Mittasch and Schneider in 1913 (1 ). The catalysts which they described were oxides of cerium, chromium, manganese, molybdenum, titanium, and zinc which had been "activated" by incorporating alkalies such as sodium and potassium carbonates. The products were methanol, higher alcohols and saturated and unsaturated hydrocarbons. Pressures and temperatures were 100-200 atmospheres and 300 to 400 C. These were... 

Addition of carbide-forming elements (e.g., vanadium, molybdenum, titanium) to the steel... 

Maintaining a safe and healthy workplace is more complex than it has ever been. New materials and new processes have created new problems. About 8,000 new chemical compounds are created each year. Production materials have become increasingly complex and exotic. Engineering materials now include carbon steels, stainless steels, cast irons, tungsten, molybdenum, titanium, aluminum, powdered metals, plastics, etc. Each of these metals requires its own specialized processes and has its own associated hazards. Nonmetals are more numerous and have also become more complex. Plastics, plastic alloys, and blends, advanced composites, fibrous materials, elastomers, and ceramics also bring their own potential hazards to the workplace. 

Nitrogen is frequently used as shielding gas. As a rule, however, argon is used in the case of elements which form nitrides, e.g. barium, molybdenum, titanium and vanadium. In order to reduce condensation of the sample and evaporation of the matrix products at the cooler ends of the cuvette, the shielding gas is usually fed in at the ends and escapes from the sample insertion hole. The flow of gas is usually optimized by the equipment... 

In the case of non-saline waters, the maximum heating rate is usually selected, as this generally reduces chemical interference. Sensitivity is also increased, particularly with such low-volatile elements as molybdenum, titanium and vanadium. It is of considerable importance to heat the cuvette to a higher temperature than the atomization temperature of the element to be determined. 

Examples of metals that are passive under Definition 1, on the other hand, include chromium, nickel, molybdenum, titanium, zirconium, the stainless steels, 70%Ni-30% Cu alloys (Monel), and several other metals and alloys. Also included are metals that become passive in passivator solutions, such as iron in dissolved chromates. Metals and alloys in this category show a marked tendency to polarize anodicaUy. Pronounced anodic polarization reduces observed reaction rates, so that metals passive under Definition 1 usually conform as well to Definition 2 based on low corrosion rates. The corrosion potentials of metals passive by Definition 1 approach the open-circuit cathode potentials (e.g., the oxygen electrode) hence, as components of galvanic cells, they exhibit potentials near those of the noble metals. 

Table 2 summarizes some of the important features of the ET-AAS technique using STPF conditions. For end-heated atomizers (see Figure la), the platform cannot be used in the determination of elements of low volatility like molybdenum, titanium, and vanadium. Elowever, all elements can be determined using STPF conditions in side-heated atomizers (Figure lb). Other than the characteristics shown in Table 2, it should be mentioned that modern ET-AAS instruments are fully automated and can work unattended, but experienced personnel are required to optimize parameters (particularly the temperature program) and ensure the quality of the results. 

Deposition of Molybdenum, Titanium and Aluminium. Proc. IX, Int. Symp. Molten Salts, San Francisco, May 1994. 

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