Perfect cutting edges thanks to laser technology
Also at this year´s Grindtec 2016 in Augsburg (16. – 19.3.) DMG MORI will again be presented in Hall 2 (Booth Nr. 2055) with 4 innovative machine exhibits. Beside its unrivalled expertise as being the market leader in 5-axis ULTRASONIC grinding of Advanced Materials DMG MORI will also focus on its expertise in the efficient machining of PCD / CVD precision tools with laser technology.
With the LASERTEC machines developed by SAUER DMG MORI has a product range that covers the needs of this industry in the best way in terms of economic and quality aspects. On the upcoming GrindTec 2016 two 5-axis LASERTEC 20 PrecisionTool machines will be presented with most representative live demos, whereby one of them will be shown fully automated with the linear magazine PH 10 I 100.
“Many tool makers are being confronted with the challenge of sustainably optimising their process chains in production, due to the increasing demand for PCD tools,” says Friedemann Lell, Sales Manager at SAUER GmbH, about the current development in this segment. The key process steps involved here are segmenting of the PCD elements and finishing of the tools. “In both cases laser technology has crystallised as the most efficient solution with the best machining results.” Friedemann Lell mentions the LASERTEC 20 FineCutting and the LASERTEC 20 PrecisionTool models as typical examples here.
The first step in the production of PCD tools involves cutting the individual PCD segments out of the 3.2 mm-thick blanks. Machining speed is a decisive factor in this step. With the LASERTEC 20 FineCutting DMG MORI has a machine in its program that significantly outperforms conventional wire eroding. Equipped with a fibre laser – 3 kW pulse power rating in the standard version – it achieves a cutting rate of 100 mm/min for a blank thickness of 1.6 mm. The LASERTEC 20 FineCutting cuts out segments from thinner blanks at a rate of 200 mm/min. But more than that: DMG MORI also has a fibre laser with a max. power rating of 4.5 kW available as an option. “This makes 300 mm/min realistic and enables cutting of PCD up to 4.6 mm,” explains Friedemann Lell. As the LASERTEC 20 FineCutting operates with five axes, the PCD elements can also be given the relief angles required later at the same time as segmentation. This makes subsequent finishing a lot simpler.
DMG MORI recently made a great innovation leap with the LASERTEC 20 PrecisionTool. The integrated technology is used here for the finishing of the PCD tools and outshines by far conventional methods such as wire eroding and grinding - especially where quality is concerned. Time and again these methods cause break-outs on the cutting edges during machining. Wire eroding only cuts through the binding material, not the diamond grains, while the mechanical grinding process causes chipping, because the grains are broken out of the material here. The fibre laser, however, produces an absolutely clean surface, because it cuts evenly through the whole PCD material. Friedemann Lell tells us: “This results in perfect cutting edges which mean that PCD tools produced in such a way have a service life that is two-and-a-half times longer than that of tools produced with conventional methods.” The edge radius is just 2 to 3 µm.