Hard metal tools

The Congo, Zambia, Canada, Morocco, and New Caledonia are considaed the main places of production of the cobalt ore. The main use of the cobalt ore was for aircraft superalloys, hard metal tools, magnets, catalysts, and pigments before the rechargeable lithium-ion battery was developed. Therefore, the cobalt oxide that could be used for batteries was low. However, the number of manufacturers producing the cobalt oxide recently has increased due to the expansion of the market In our company, various cobalt raw materials produced by 6-7 companies are always being evaluated. 

Sintered hard metal tools are now well established in forestry and wood working applications, where they render very high levels of productivity, closer dimensional tolerances, better surface finish and cheaper costs. For example ... 

The main advantages of ECM are that the rate of metal machining does not depend on the hardness of the material, compHcated shapes can be machined on hard metals, and there is no tool wear. 

Niobium carbide is used as a component of hard metals, eg, mixtures of metal carbides that are cemented with cobalt, iron, and nickel. Along with tantalum carbide, niobium carbide is added to impart toughness and shock and erosion resistance. The spiraling rise in the price of tantalum has spurred the development of a hafnium carbide—niobium carbide substitute for tantalum carbide (68). These cemented carbides are used for tool bits, drill bits, shovel teeth, and other wear-resistant components turbine blades and as dies in high pressure apparatus (see Carbides). 

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. 

Dreyer and co-workers, Development and Tool Lfe Behavior of Super-Wear Resistant Multilayer Coatings on Hard Metals, Book No. 278, Metals Society (London), 1982, pp. 112-117. 

The lathe is geared up to at least 3,GOO revolutions per minute. An ordinary spinning tool is placed in the lathCj tubes of the desired metal are placed in the chuck and a fine oxy-acetylene flame is focused on the point where the spinning tool is pressed against the metal. The torch is geared to the same carrier as the spinning tool, and so moves with it automatically. Perfectly round balls of hard metal, sealed at both ends, can be made in this manner. 

Forging and extrusion do not involve the removal of metal by means of cutting tools. Many important shaping processes are based on cutting operations. Cutting tools are made of special steels (tool steels), hard metals, oxide ceramics, and diamond. 

Niobium is used to inhibit intergranular corrosion in austenitic steels and as carbide in hard carbide tool compositions. The metal is in commercial production and a more extensive use of it may be expected. 

Improvements in quality (longer lifetime of tools, coatings of hard metals, etc.). 

Brown—490. Gravers and turuiiig tools for hard metals also percussion-lock gun tulies. 

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