ZOX coated end mills up aluminium cutting speeds Zirconium nitrogen oxide coated cuttings tools overcome 'sticky' swarf removal and will increase surface finish quality and speed of machining aluminium. A new generation of end mills incorporating a ZOX coating will significantly reduce the machining times of aluminium materials. The zirconium nitrogen oxide ZOX coating is titanium-free and is featured on milling tools within the Garant HPC premium brand range in the 2006/7 Hoffmann Group-Perschmann tooling catalogue.

A particular challenge when machining aluminium is the reliable removal of the sticky swarf generated, as any build up has an adverse influence on surface finish and cutting speed.

The ZOX coating minimises the coefficient of friction at the cutting face and guarantees efficient evacuation of machining chips.

Garant tools incorporating the coating also have large flutes that are polished as well as specially designed hollows that optimise the process of swarf removal.

ZOX coated cutting tools are particularly well suited to machining aluminium workpieces where a high surface finish quality is required.

As the coating is free of titanium, the tools also meet aerospace industry requirements for the contamination-free machining of aluminium alloys.

'In practical tests, the tools with ZOX coating have performed better than previous tools in all respects,' said Robert Riesinger, application technician at the Hoffmann Group.

A solid carbide roughing end mill was used to machine AICuMg2 aluminium alloy at a cutting speed of 1,130m/min, at a feed rate of 0.224mm and a depth of cut of 20mm.

'The results demonstrate that users will benefit from reduced machining times and production costs along with the bonus of improved surface finish,' concluded Riesinger.

In its 37th tool catalogue issued on 1st August 2006, Hoffmann offers seven different solid carbide HPC end mills with ZOX coatings.

The range includes two-tooth solid carbide micro slot drills, two-tooth micro torus cutters, two-tooth micro full radius ball-nosed slot drills, three-and four-tooth roughing end mills without knuckle profile, six and eight-tooth end mills and a variety of two-tooth micro ball-nosed slot drills.

Looking ahead, the success of the ZOX coated tools points towards an extension of the product range.