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Fig.2: TiN PACVD
Ø 1050 mm.
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Coatings against wear
In these last 20 years it has been noticed that there is a continuous and progressive expansion of coatings against wear. Titanium nitride, the first and more famous of the coverings, thanks to its high hardness and to its coefficient of friction inferior to the steel, allows to reduce considerably the abrasive wear, main cause of the reduction of tool performances. Subsequently new coatings have been proposed aiming to solve specific problems so that today unthinkable performances are possible like dry and high speed work.
Recently new kind of coverings appeared on the market, trying to reduce the coefficient of friction (bringing it from about 0.8 of steel against steel to 0,02-0,04). CRT is able to offer a coating resulting in the combination of an extremely hard and a self-lubricating one (Dry-tool). The offer therefore is diversified to allow to face, with a cautious choice, not only the problems of abrasive nature, but also corrosive ones.
From their natural field of application, the tools are expanding constantly and today there are numberless examples of improvement in die-casting or in the aluminum extrusion, in the plastic injection, in the drawing or sheet punching and even in the food industry and in the dental prosthesis. In many cases, the advantages are not only measured in terms of particular hardness of coatings but also of less maintenance time and machine stops, less rejects, increase of working speed, possibility to resume the tool before it is completely damaged etc. |
