Cobalt-tungsten carbide

Thermal spray processes can be used to give coatings of chromium carbide or nickel chromium for erosion resistance, copper nickel indium for fretting resistance, tungsten carbide cobalt for wear and abrasion resistance, and even aluminum siHcon polyester mixtures for abradabiHty. 

Tungsten carbide-cobalt alloys, 4 663 Tungsten carbides, 25 372-373, 385 uses for, 25 388... 

Special carbide tools also will often contain various percentages of titanium, tantalum, niobium icolumbium). and hafnium carbides, along witii die tungsten carbide. Chromium and vanadium carbides are also added to produce special, fine-grain-size grades of cemented tungsten carbide-cobalt materials. See Fig. 1. 

Titanium carbide/nickel and titanium carbonitride/nickel cermets are considered excellent substitutes for tungsten carbide/cobalt cermets because nickel is more abundant and less expensive than cobalt.2... 

In order to improve the wear resistance of machining tools made of hard metals, steel, tungsten carbide cobalt, titanium aluminide, titanium and silicon substrates have been coated with SiBNsC via CVD of TABB [107, 108]. Layers produced in this fashion are dense and exhibit a Vickers hardness of 1000-2300 kg mm S depending on the specific process parameters. 

Cederqvist studied 17 different tool materials to friction stir weld 50 mm thick copper (Ref 33), and the first material evaluations were for use as the tool pin. Tungsten carbide-cobalt pins provided the initial welding parameter development, but tool life issues (due to large spindle eccentricities) made this tool material impractical for production. Likewise, eccentricity issues caused PCBN, alumino-silicate, and yttria-stabilized zirconium oxide pins to fail within the plunge or dwell sequence of the friction stir welds. A majority of e pins manufactured from refractory metals (four molybdenum-base and three tungsten-base) did not have dimensional... 

Physical Description A mixture of tungsten carbide, cobalt, and sometimes other metals metal oxides or carbides. 

Tungsten Carbide-Cobalt, Tungsten Carbide-Nickel,... 

Tungsten carbide (WC), the hard phase, together with cobalt (Co), the binder phase, forms the basic cemented carbide structure from which other types of cemented carbide have been developed. In addition to the straight tungsten carbide - cobalt compositions - cemented carbide may contain varying proportions of titanium carbide (TiC), tantalum carbide (TaC), and niobium carbide (NbC). These carbides are mutually soluble and can also dissolve a high proportion of tungsten carbide. Also, cemented carbides are produced which have the cobalt binder phase alloyed with, or completely replaced by, other metals such as iron (Fe), chromium (Cr), nickel (Ni), molybdenum (Mo), or alloys of these elements. 

Toxicity on Lung. Experimental studies in animals have shown that W metal, tungsten carbide, and tungsten carbide-carbon alloy are not very toxic [29-33]. On the other hand, inhalation of tungsten-carbide-cobalt alloy in guinea pigs induces an inflammatory reaction accompanied by peribronchial fibrosis and bronchial mucosa hypertrophy [31,32]. 

Figure 2. Sectioning of a fixed, non-embedded round specimen. The positions of the cut surfaces are labeled (a)-(d). The scanning electron micrographs indicate the sectioning quality of the round steel specimen, which is plasma-sprayed with tungsten carbide-cobalt.

Detonation gun applied, tungsten carbide + cobalt and chromium. 

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