Precision milling hard metals in practice

On 27 November, Diatool demonstrated that it is possible to mill hard metal (cemented carbide) with precision. In addition to the five milling demonstrations using the Sirris precision milling machine, other applications and types of tools for processing this sort of working material were also shown during the presentation.

During a successful workshop held at the Sirris Precision Manufacturing Lab in Diepenbeek, Diatool showed tools for milling, drilling and tapping hard metal. These technologies can offer a faster and more cost-effective alternative for certain applications than the normal processing technologies (sparking, grinding) when using this type of material.

Milling hard metal is possible thanks to the patented, hard (9000 HV) diamond coating applied to the sides of the metal cutting edges. Further properties of the diamond coating in addition to its hardness, are the very high levels of adhesion it has with the hard metal substrates.

(Source : Union Tool)

The most important factors for making a success of milling hard metal include:

  • a rigid machine that can absorb the high cutting forces
  • maximum rotation accuracy at the tool tip
  • minimum expansion of the spindle with respect to the shaft length caused by temperature fluctuations
  • cooling of the machining process by way of compressed air, because this gives the longest tool life-cycle - alternatives include oil mist and oil lubrication.

During the milling demonstration on the Sirris precision milling machine, a Torx profile was milled in the shaft of a hard metal tool with a hardness of 91.5 HRA.

(Source : Union Tool)

It emerged from the 25 people present that there is certainly interest in this apparatus. A few reactions:

"Being able to mill a sintered shape directly could remove one production phase".

"Milling hard metal presents opportunities for introducing cutting edge geometries in tools that cannot normally be ground".

This workshop took place within the scope of the IWT research project 'Precision Manufacturing for new and better products'.