Due to titanium’s high strength and low thermal conductivity, finishing this material requires specialized tools and well-thought-out milling strategies. With a special ta-C coating, Pokolm’s NV01 ball nose end mill achieves excellent surface finishes, even though it was primarily developed for machining non-ferrous metals.
Titanium is rightly considered the supreme challenge in machining. The combination of high strength, toughness, and low thermal conductivity poses a challenge to both the tool and the machine. While roughing involves enormous forces, finishing usually requires delicate precision. Especially when finishing complex geometries with ball nose end mills, the challenge lies in finding the perfect balance between surface finish and process reliability.
But what should you do if you don’t have a “titanium specialist” tool with a long service life in your tool cabinet for a complex geometry? If conventional tools are used, the high thermal stress on the cutting edge leads to rapid wear and poor surface quality.
In practice, one often faces challenging installation situations as well. A specific example illustrates the problem: To reach deep cavities, a tool with a total length of 422 mm is required, and this overhang makes it highly susceptible to vibration.
The solution to these challenges may lie in using a Pokolm NV01 ball nose end mill. Although this cutting tool is primarily designed for material group N (non-ferrous metals and plastics), its special ta-C coating makes it a high-performance alternative for titanium.
A coating of tetrahedral amorphous carbon (ta-C) is a diamond-like layer with extremely high hardness and high wear resistance. The secret behind Pokolm Premiumtools: The ta-C coating is designed in such a way that it enables titanium machining as a “secondary application” for finishing operations.
Strategy and the right parameters are key to success:
| Ball nose end mill - NV01 | 164126 |
| Arbor | 350 16 A63S |
| Vc (cutting speed) | 90 m/min |
| n (revolutions) | 1790 1/min |
| fz (feed per tooth) | 0,12 mm |
| Vf (feed rate) | 430 mm/min |
| ap (depth of cut) | 0,3 mm |
| ae (width of cut) | 0,6 mm |
To compensate for the instability of the 422-mm-long arbor, a pulling strategy from bottom to top is employed.
A high-quality TaC coating, combined with a tailored milling strategy, makes it possible to achieve excellent finishing results in titanium – even with tools that are actually designed for non-ferrous metals. Once again, it is clear that in modern manufacturing, technical expertise in coatings is often just as important as the tool geometry itself.