Diamant-Gesellschaft Tesch GmbH
Carl-Goerdeler-Str. 14
D-71636 Ludwigsburg
KNOW-HOW
Superhard materials
Definition
The installation spaces for devices, systems, machine and motor components existing today are getting smaller and smaller. By contrast, the mechanical loads on the components are growing. This leads to the development and use of materials which have to meet these high requirements and whose mechanical machining becomes increasingly difficult.
In cases where the machining of work pieces by means of conventional cutting materials begin to fail, our competence in developing diamond and CBN tools shall be applied.
Diamond
Diamond is the hardest solid material occurring in natural form. It consists of pure carbon in a crystalline structure.
Nowadays, natural diamonds are mostly used for dressing processes.
In tool construction, synthetic diamonds are generally used, which are produced at high pressure and high temperatures. Compared to corundum or silicon carbide, diamond shows a much greater hardness and resistance to mechanical wear.
If the thermal stress is too high (approx. 800° C), there is a risk of transformation into graphite.
Work piece materials - Grinding:
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Hard short-chipping materials: CBN, gems, ceramics, cermet, carbide, glass, ferrite, graphite etc.
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Machining of green ceramics: ceramic blanks, carbide blanks
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Hard facing alloys and welded alloys
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Fibre reinforced materials/composites: carbon fibre reinforced plastic (CFRP), glass fibre reinforced plastic (GRP), Kevlar etc.
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Carbide: wear protection hard metals
(no cutting materials)
Work piece materials - Turning, milling, drilling, reaming:
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Non-ferrous metals: Al alloys (mostly pressure die casting), copper, bronze, brass, etc.
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Plastics: thermosetting plactics and thermoplastics
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Fibre reinforced materials/composites: carbon fibre reinforced plastic (CFRP), glass fibre reinforced plastic (GRP), Kevlar etc.
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Green machining: ceramic blanks, carbide blanks
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Carbide: wear protection hard metals
(no cutting materials)
Graphite, hard carbon, hard paper
Graphite, hard carbon, hard paper
CBN
CBN is the hardest known substance next to diamond. It is made from boron and nitrogen in a process similar to the diamond synthesis. It differs from the synthetic diamond in its higher thermal stability. Compared to conventional cutting materials, CBN offers advantages, when machining steels that are difficult to cut and whose hardness is more than 50HRC.
Work piece materials
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Materials with affinity for carbon (high-alloy steels, HSS, hot and cold working steel, hardening, tempering, ball bearing and spring steels as well as stellite and nickel, chromium, titanium and cobalt base superalloys, chilled cast iron, grey cast iron, etc.)
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Sintered material with affinity for carbon (PM steels)
Outlook
In the future, the use of extremely hard cutting materials such as CBN and diamond for the grinding, turning, milling, reaming and dressing operations will become even more important due to the use of new materials.
