"Thick" PVD coatings |
"Thick" coatings on indexable inserts ensure longer tool lives
Numerous benefits with the PVD method
In order to be able to react quickly to new machining requirements and not be left behind, it is essential to recognize trends at an early stage. This also applies to companies in the coating industry. To achieve this, it is essential to cooperate closely with tool manufacturers and users.
It is almost ten years since the first attempt to create the mostly thin PVD coatings with thicker coatings of up to 8 µm. Their successful use, especially on indexable inserts, opened up a considerably wider field of application for the PVD technology. The "thick" PVD coatings, now produced by CemeCon, are customer-
specific coating specifications, for which coating materials such as ALOX SN² and ALOX SN² gold are adapted to the particularly insert types and/or the customer requirements. These coatings have been used successfully for a number of years in milling and lathing operations.
Just how thick is "thick"?
What does a coater consider to be a "thick" coating? After all, we're only talking about a few thousandths of a millimeter - which do however make a difference. Most coatings with thicknesses between 10 and 12 µm are nowadays produced using the CVD method. The coating compositions are primarily TiN, TiCN and aluminum oxide in combination with one another. However, the trend as well as demand is towards using a significantly wider range of materials for coating. Tool manufacturers want the option of combining elements such as aluminum, chrome and silicon in order to adapt the properties of the coating materials even more precisely, thus equipping themselves in the best possible way for new challenges and materials. At present, the only way to achieve this goal is through using PVD technology. This enables the user to benefit from additional advantages such as ultra-smooth coating surfaces and low process temperatures to avoid the risk of the substrate becoming embrittled.
Accordingly, oxidic coatings are no longer beyond the limits of PVD technology. Using elements such as aluminum, chrome, zircon and other potential components, new materials are set to conquer the market in coming years and open up completely new possibilities. These coating materials can be produced in combination with supernitrides, for example, in PVD-typical 3 µm coatings as well as 8 or 10 µm and even greater coating thicknesses - depending on the properties of the cutting edge and the application. In addition, new pretreatment and follow-up treatment methods are available which, combined with the optimum coating material, enable a wide range of customer products to be produced.
Longer tool life with thick coatings
The advantages of thicker coatings are clear: on one hand, the substrate is protected against effects resulting from the machining process such as high temperature. Secondly, with double the coating thickness, the user obtains almost 100% tool life in some applications. Both the coating tools that are already produced by CemeCon as well as future developments are suitable for lathing and rough milling applications in all common forms of steel and castings.
In Würselen, CemeCon produces its coating solutions with its own production lines for the following individual machining tool groups: indexable inserts, shaft tools and hob cutters. In these production lines, production steps, peripherals, systems technology and coating materials are all precisely coordinated to meet the requirements of the tool group in question. The result of a fine-tuned combination of processing steps, coating materials and coating thicknesses produces an almost unlimited variety of individual coatings which cannot be compared with one another and which allow each customer to distinguish him from his competitors.
A technology for (almost) every purpose
Companies which already use their own in-house coating technology as well as those planning to acquire such systems in the future open themselves up to additional possibilities with the new development trends in PVD technology:
In the past, manufacturers of indexable inserts in particular had to come to terms with various technologies in order to cater for all the requirements. With the new PVD developments it will soon be possible to meet a much wider range of requirements using a single technology. From processing steps such as mill cutting (planing, rough turning etc.), to burring and lathe-processing - in future it will be possible to process all this and more using a single system. It will also be possible to coat other cutting materials such as ceramics.
Another matter of the utmost importance to industrial production is the protection of the environment:
the PVD method is environmentally-friendly and does not produce any damaging waste products!
Coating competence
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