Hardness 209 cutting tools

Hardness Cutting tools (SiC whisker-reinforced AI2O3, Si3N4)... 

Interstitial Compounds. Tungsten forms hard, refractory, and chemically stable interstitial compounds with nonmetals, particularly C, N, B, and Si. These compounds are used in cutting tools, stmctural elements of kilns, gas turbines, jet engines, sandblast nozzles, protective coatings, etc (see also Refractories Refractory coatings). 

The cubic BN crystals may also be bonded into strong bodies that make excellent cutting tools for hard iron and nickel-based alloys. Such tools produce red-hot chips and permit the wider use of tough, high temperature alloys which would otherwise be prohibitively difficult to shape (12,20,21) (see... 

Cutting tools Hardness, toughness Alumina, siolons... 

Cheapest of all are the particulate composites. Aggregate plus cement gives concrete, and the composite is cheaper (per unit volume) than the cement itself. Polymers can be filled with sand, silica flour, or glass particles, increasing the stiffness and wear-resistance, and often reducing the price. And one particulate composite, tungsten-carbide particles in cobalt (known as "cemented carbide" or "hard metal"), is the basis of the heavy-duty cutting tool industry. 

The use of tungsten carbide alloyed with cobalt, well known as Hard Metal is used for cutting tools because of its excellent wear resistance but finds little use as a corrosion resistant material. 

In diamond, each carbon atom forms single bonds with four other carbon atoms arranged tetrahedrally around it The hybridization in diamond is sp3. The three-dimensional covalent bonding contributes to diamond s unusual hardness. Diamond is one of the hardest substances known it is used in cutting tools and quality grindstones (Figure 9.12). 

Evaporation is used extensively for the deposition of aluminum and other low melting-point metals as well as hard coatings such as TiN for cutting tools, decorative coatings (jewelry), and for the metallization of paper and fibers. It is also a major coating... 

Hard coatings for cutting tools and erosion applications. 

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