Drilling

Economical drilling with SN² Supernitrides

Many sources of error can make the drilling process unproductive. For chips and heat to flow off correctly, tools with excellent hot hardness, high wear resistance, sharp cutting edges and smooth surfaces are required. Tool manufacturers offer their customers efficient solutions. With the right coating – adapted to the tool, workpiece and all other process parameters. This is made possible by the SN² Supernitrides from CemeCon. These coatings are smooth, droplet-free, hard and at the same time tough, and make tools fit – especially for high-tech applications.

Jamming chips, heat build-up, changing loading of the cutting edges, ridges or smeared-on material – the list of potential error sources during drilling is a long one.

Machinists, who still bank on conventional drill bits in the respective applications, e.g. in automotive industry and increasingly also in the aerospace sector are at a loss as how to solve these problems. Aborting the process or frequent tool changes are only a few of the consequences resulting from the use of incorrect or uncoated drill bits. In contrast, modern coating solutions offer not only innovative microgeometries, but also enormous potentials.

Manfred Weigand, Product Manager Round Tools at CemeCon says,
“Around 75 percent of the drill bits used are coated, however all too often with rough coatings ‘off the rack’.

Innovative coatings are what’s needed to realize high-speed drilling, but also increasingly deep-drilling operations with all the current and future demanding requirements. They have to have outstanding adhesive properties, be extremely hard and at the same time tough. In addition, they also have to be extremely smooth and droplet-free, and be highly resistant to oxidation and wear.”

Adapted Supernitride power

All these requirements are simultaneously met by the CemeCon SN² Supernitrides. Their especially tension-free coating structure enables the wear volume necessary for drilling operations.

The fault-free surface ensures frictionless chip removal. As a result, the machinist can optimally machine not only hardened and tempered steel, but also high-tech materials with SN² Supernitrides optimized for the drilling application.

“Without coatings adapted to the respective application, modern cutting tasks are unsolvable and first-class shape and surface qualities cannot be achieved. Tasks that could hardly be more different require exactly matched tool geometries. And of course, that also applied to the right coating,” explains Manfred Weigand.

Just how important a coating solution customized to fit the drilling operation is, becomes apparent, for example, when drilling 14NiCr10. Here the ALOX^® SN² Supernitride coating especially well-suited for drilling operations achieve a considerably higher number of drilled holes than other solutions – 45 percent more in the specific example.

Source: FACTS 26 page 8

From 6 to 90 with SN²

Precision processing of hard materials much stresses the tools being used: high-strength types of steel demand everything from these tools and has to be paid for in most cases through strong wear on the tools. In order to render such processing more economic, more and more tool manufacturers are relying on high-performance coating materials – like supernitrides from the SN²-class provided by CemeCon.

Inside processing with micrometer accuracy is as such already a challenge for tools and machines. And when also extremely hard materials need to be processed, the combined expertise is much in demand: then tool manufacturer and coating professionals will optimise the solutions which are customised with respect to the specific task – frequently with enormous performance increases:

Process optimisation through SN²

At the company Helmut Christmann GmbH from the Swabian town of Birkenfeld there were difficulties regarding processing stability when precision processing boreholes in precision machined subassemblies made of X153CrMoV12-(1.2379) steel.

Helmut Christmann, Managing Director of Christmann GmbH: “With the tools used to date it was absolutely not possible to precision machine more than six boreholes in one go in this highly wear-resistant type of steel – absolutely inadequate for efficient production. For this reason we talked to the company Wohlhaupter GmbH as one of our tool suppliers. And they had a solution”.

In the development department of the company Wohlhaupter the engineers from Wohlhaupter adapted together with the ex-perts from CemeCon both tools and coating for this particular application – among other things for the miniature turning out cutting edges of the DigiBore tools.

“The results were overwhelming” says Dipl.-Ing. Holger Rabe, head of project management for indexable inserts at Wohlhaupter. “Through the improved process thanks to the SN² coating we can now precision process instead of six bores in the past, now a total of 90 with a single turning out cutting edge tool. And this at the highest precision of 2 µm in a single work step”

Micrometer accurate precision processing in a single work step

Such results have at all only become feasible mostly owing to the extremely smooth surfaces of the TINALOX^® SN² coating material. The TINALOX^® SN² material allows for perfect removal of the chips and permits, owing to its high degree of toughness combined with very high hardness, re-liable processing of steel or cast-iron, for example. The coating material is the ideal solution for the applications run at the company Christmann GmbH – proven in an impressive way through the enormously extended service life and the resulting production cost savings”.

Source: FACTS 29 page 3-4