The “smallest” world sensation of 2022: the new micro milling cutter from Mikron Tool!
Press release, September 2022
According to the Global Innovation Index 2021, Switzerland is the country with the highest level of innovation worldwide. Technology-oriented companies such as the Swiss precision tool manufacturer Mikron Tool from Ticino make valuable contributions towards this. In fact, this company surprises once more with a new development that is well worth seeing. A “small” world sensation!
The new, outstanding milling cutter will be presented for the first time at IMTS 2022
The 250 employee company is presenting its new high-performance micro milling cutter designed for roughing and finishing the most difficult-to-machine materials at the IMTS in Chicago. The new CrazyMill Cool Micro Z3/Z4 – the smallest with integrated cooling and the first with material-specific cutting edge geometries – is available in the diameters from 0.2 mm to 1.0 mm (.008“ – .039“) with a milling depth of up to 5 x d.
Designed for high-performance materials such as stainless steels, titanium and titanium alloys, heat-resistant alloys (e.g. Inconel and Nilo) and CoCr alloys, it offers a significant increase in performance and maximum process reliability compared to conventional standard products. Above all, it demonstrates its strengths in side and slot milling as well as in milling with spiral interpolation.
The challenge of miniaturisation
The increasing miniaturisation of workpieces requires tools that are both high-performance and reliable, even for the smallest applications. They are increasingly sought after in medical engineering, in the watch and jewelry industry and in the electronic hardware industry. In response to this need, Mikron Tool has developed an exceptional new milling cutter for micro-machining. For the first time, the engineers at Mikron Tool have succeeded in transferring complex high-performance cutting edge geometries to micro milling cutters. This requires a high level of expertise, not just in development work. From a production point of view, it is also a major challenge to implement such complex geometries in milling cutters with diameters smaller than 1.0 mm (.039”).
The smaller the cross-section of the tool, the more demanding is manufacturing them while maintaining quality requirements and tolerances. This requires state-of-the-art high-precision grinding centres and diamond grinding wheels with ultra-fine grit.
High-precision digital measuring equipment is used throughout the production process to ensure the high quality standards, including custom-made digital microscopes with up to 2000x magnification. This is not enough on its own. Thanks to the competence of the grinding specialists in the nano-tools production department, Mikron Tool produces these milling cutters with absolute maximum precision in the correction range of 0.1 µm (3.94 µin). This demands highly meticulous grinding skills from the grinding machine operator.
New material-specific cutting edge geometries S and SX
The specific material properties and the very different machining behaviour associated, were one aspect that played a decisive role in the development of this milling cutter. The R&D department therefore took a close look at this issue during the development of the new milling cutter and the result was remarkable. Two main groups of materials were defined, for each of which a specific cutting geometry was developed:
• Geometry S was specially developed for stainless steels, structural steels, non-ferrous metals and titanium alloys. It is characterized by a higher cutting capacity for materials with a specific cutting force of less than 2250 N/mm2 (326’335 psi).
• Geometry SX, featuring a special cutting edge protection, is suitable for materials with a specific cutting force greater than 2250 N/mm2 (326’335 psi) such as heat-resistant alloys and CoCr- alloys.
For the first time, this allows high-performance milling of hard and difficult-to-machine materials in micro-production. Furthermore, the material-specific geometries process the material so perfectly that the formation of burrs is practically avoided.
Tool deflection is a thing of the past
Tool deflection during milling is a considerable problem with small tool diameters, which is further exacerbated with materials that are difficult to machine due to higher cutting forces.
The newly developed geometries prevent tool deflection by combining high cutting ability with robustness, depending on the material, which inevitably leads to greater overall tool stability. The result: significantly higher removal volumes with perfect contour accuracy and significantly longer tool life.
Stay cool!
High temperatures and temperature changes around the cutting edge are extremely critical issues for any high performance materials used in milling processes, especially when it comes to micro-manufacturing. Mikron Tool benefits from its pioneering role in milling cutters with integrated cooling. The revolutionary and proven cooling concept (patented) of the CrazyMill Cool milling cutter series has been transferred to the new micro milling cutter – including the smallest diameters! – which leads to excellent results.
At the heart of the cooling concept are the cooling channels integrated into the tool. Thanks to their special shape, they deliver significantly more coolant into the milling area resulting in constant and more efficient cooling of the cutting edges.
This enables to achieve the highest cutting values and significantly better material removal (compared to commercially available micro cutters).
In addition, the massive cooling jet flushes the chips away from the machining area which means that repeated cutting of the chips does not take place. The result is excellent tool life and a ultrafine surface finish.
Edge wear prevention down to the µin range
To produce precise geometries and ultra-fine cutting edges, it is important to make the right choice when it comes to carbide the tool is made from. To meet the high demands, Mikron Tool relies on state-of-the-art ultra-fine grades with high wear resilience combined with high fracture resistance. The grain size here is less than 0.5 µm (19.69 µin).
Mikron Tool also makes use of the most up-to-date coating technology. The new revolutionary Exedur SNP coating offers excellent wear resistance even at extreme operating temperatures. The high layer smoothness and the precise uniform layer thickness evenly protect all contours without impairing the cutting ability.
Based to this coating, tool life is significantly increased, which results in a high level of process reliability. As the coating is chrome free, a cross contamination on medical part is avoided.
First empirical values from the field of medical technology
The first small series of the new CrazyMill Cool Micro has already rolled off the production line and is in the test phase at a medium-sized medical technology manufacturer. The company manufactures components for surgical instruments on six turn-mill centres. The producer was looking for a micro-machining solution for martensitic chrome steel. They were unsatisfied with the performance of the micro-milling cutters they had been using and were looking for alternatives. Mikron Tool recommended using geometry S for milling martensitic chrome steel. Milling quality, tool life and burr formation have greatly impressed the customer and enabled him now to run unmanned shifts. This is the first report from the medical manufacturing sector on the latest high-performance micro milling cutter series from Mikron Tool.
A star is born
“Practical experience shows that Mikron Tool has once again hit the jackpot with this development. The fact that this tiny tool delivers high performance can also be seen from a chrome steel roughing application that we carried out in our Technology Center:
ø = 0.6 mm (.0236”); n = 30 000 rpm; ap = 0.5 mm (.0197”); ae = 0.08 mm (.0031”), the feed rate of the milling cutter is 540 mm/min (21.26 in/min). For a 0.6 (.0236”) solid carbide milling cutter, these are outstanding values that set new benchmarks,” says Markus Schnyder, Managing Director.
“As an innovative and agile cutting tool manufacturer, we are technology-driven and continuously invest in research. The best thing about it is that our employees always actively drive these developments forward with a high level of motivation. The cooperation between the grinding department and R&D on this project was an extraordinary team effort. With this new development, we have ensured the reliable and economical production of components in the smallest of dimensions, now also in high volume production. A star is born! “
Mikron Switzerland AG, Division Tool
Via Campagna 1
CH-6982 Agno
Tel. +491 91 610 4000
mto@mikron.com
www.mikrontool.com