Cobalt base materials

Table 4-15 lists base materials Elliott has tested. This list, which is continually being expanded, includes low alloy steels, high alloy iron base, nickel base, cobalt base materials, and odiers. Table 4-16 shows some of the coatings Elliott has tested. The list indicates die supplier, coating designation, and major components of the coating composition. 

By the way, LiCoO has been used mainly as the cathode material in the lithium-ion battery for mobile phones because of high-energy density. However, the rapid rise in price for the lack of the cobalt resources has promoted the hybridization between the cobalt-based material and the manganese-based material with the spinel structure. Further, it has been confirmed that this hybrid material can have the same energy density as that of the conventional one, so the hybrid-type batteries came onto the market since 2004. It is expected that the share of this type of battery will expand further in the future. 

Although the layered Ni-Mn-based cathode material has beeu placed on the market in the form of single or mixed cathode material, hae we will explain the spinel manganese-based material. This compound also has been placed on the market in the form of single or mixed with a layaed nickel- or cobalt-based material. 

The most important factor for a battery is how to increase the active material in the cell with the limited volume. Therefore, the capacity per unit volume is a key factor. The cobalt-based material is still a promising material because an 808 mAh of capacity per unit volume is achieved for the sake of its higher density. Moreover, the shape of the discharge curve also is important because the design of the electric circuit for the charge/discharge control of battery is easier for its sloped curve. 

In Sect. 2.5.1 the design policy of the cobalt-based material used for more than 10 years is described in detail. The changes of design policy, which depends on the safety or charge/discharge conditions of battery, are examined and the current states of nickel- and manganese-based materials, which will appear in the market within 1-2 years, are described. 

Cobalt is applied as a base metal for a number of alloys, as an alloying element, and as a component of numerous inorganic compounds. Table 3.1-83 lists its major applications. Cobalt and cobalt-based materials are treated extensively in [1.90,91]. 

In order to enhance activity, two different pathways have been considered one for iron-based materials and the other for cobalt-based materials. Preparation might differ, whereas the products are the same in principle, with the metal ion forming the active center in a chelate stmcture. Several aspects have to be considered in order to explain the activity of such catalysts. By the thermal treatment of these precursor stractures M-N2/4-centers are formed, which resemble the stmcture within the TMPP-complex with a chelate-like bonding of the metal ions. The most important aspect is that the cormection to the substrate as well as... 

Welded or spray and fused coatings, including nickel or cobalt-base materials with high carbide content, deposited at least 2 mm (0.08 in.) thick... 

Appllca.tlons. The principal appHcations of nickel-base superalloys are in gas turbines, where they are utilized as blades, disks, and sheet metal parts. Abcraft gas turbines utilized in both commercial and military service depend upon superalloys for parts exposed to peak metal temperatures in excess of 1000°C. Typical gas turbine engines produced in the United States in 1990 utilized nickel and cobalt-base superalloys for 46% of total engine weight (41). However, programs for future aerospace propulsion systems emphasize the need for lightweight materials having greater heat resistance. For such apphcations, intermetallics matrix composites and ceramic composites are expected to be needed. 

The cobalt deposition rate on new, replacement, or decontaminated recirculation piping surface has been reduced by pretreating the piping using an atmosphere of oxygenated wet steam to form an oxide film (25). Studies have been conducted for both PWRs and BWRs to reduce the cobalt content of materials used in the nuclear parts of the plants, particularly in hardened and wear surfaces where cobalt-base alloys ( 50% Co) are used (26). Some low cobalt materials have been developed however, the use of the materials is limited to replacement parts or new plants. 

Nonferrous alloys account for only about 2 wt % of the total chromium used ia the United States. Nonetheless, some of these appHcations are unique and constitute a vital role for chromium. Eor example, ia high temperature materials, chromium ia amounts of 15—30 wt % confers corrosion and oxidation resistance on the nickel-base and cobalt-base superaHoys used ia jet engines the familiar electrical resistance heating elements are made of Ni-Cr alloy and a variety of Ee-Ni and Ni-based alloys used ia a diverse array of appHcations, especially for nuclear reactors, depend on chromium for oxidation and corrosion resistance. Evaporated, amorphous, thin-film resistors based on Ni-Cr with A1 additions have the advantageous property of a near-2ero temperature coefficient of resistance (58). 

The abrasion resistance of cobalt-base alloys generally depends on the hardness of the carbide phases and/or the metal matrix. For the complex mechanisms of soHd-particle and slurry erosion, however, generalizations cannot be made, although for the soHd-particle erosion, ductihty may be a factor. For hquid-droplet or cavitation erosion the performance of a material is largely dependent on abiUty to absorb the shock (stress) waves without microscopic fracture occurring. In cobalt-base wear alloys, it has been found that carbide volume fraction, hence, bulk hardness, has Httie effect on resistance to Hquid-droplet and cavitation erosion (32). Much more important are the properties of the matrix. 

Lucas, L. C., Buchanan, R. A., Lemons, J. E., and Griffin, C. D., Susceptibility of Surgical Cobalt-Base Alloy to Pitting Corrosion , Journal of Biomedical Materials Research, 16, 799-810 (1982)... 

Morral, F. R., Crevice Corrosion of Cobalt Based Surgical Alloys , Journal of Materials, 1, 384 (1966)... 

In recent years, the spraying process has been adapted for hard facing, using the chromium-nickel-boron alloys which have become known as Colmonoy. More recently still, the cobalt-base Stellite alloys have also been used. These materials in powder form are sprayed on to the surface in the usual way. The deposit is afterwards heat treated by a torch, so that fusion takes place. The process is often known as spray-welding. Such coatings are primarily used for hard facing under wear conditions, but as the Anal surface is nickel-chromium or cobalt-chromium they exhibit very high anticorrosive properties. 

Economics. Comparison of the material and energy balance for our process and the cobalt-based BASF higher olefin process (8), we foimd that our process reduced the capital investment required by over 50% due to the fact that we require far fewer unit operations, and because the operating pressure is much lower. In sutmnary, the thermomorphic solution developed by TDA allows easy catalyst recycle, which, when coupled with the lower pressure operation possible with Rh catalysts (compared to the cobalt-based process) lowers both capital and operating costs for current oxidation (oxo) plants of similar capacity. 

Amidocarbonylation converts aldehydes into amido-substituted amino acids, which have many important industrial applications ranging from pharmaceuticals to detergents and metal-chelating agents.588 Two catalyst systems have been developed, a cobalt-based system and, more recently a palladium-based system. In the cobalt system, alkenes can be used as the starting material, thus conducting alkene-hydroformylation, formation of hemi-amidal and carbonylation in one pot as... 

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