EMO 2013 showcases PM hard materials - Part Three

EMO (Exposition Mondiale d’Outils) 2013 was held in Hanover, Germany late last year. In the thiird part of his review, Consulting Editor Ken Brookes looks at milling products on show at the event.

Guhring CFRP milling cutter

The machining of materials such as carbon fibre reinforced polymers (CFRP) is a growing challenge for tooling manufacturers. For the latest generation of this high-tech material, effective high-tech tools are required to prevent delamination or fibre projections on the component as well as thermal damage whilst operating with extreme efficiency.

The problem is that, with the new CFRP varieties, there is a noticeable trend towards reduced resin content and unidirectional fibre orientation. Whilst woven fibres are firmly embedded in the resin fibre matrix, in unidirectional CFRP they lie next to each other in the resin. The result is a lack of interlocking embedding. This considerably affects the reliability of the machining process as, for example, milling can easily cause fibres to tear out of the composite. The higher the cutting forces, the greater the effect.

Typical delamination of a milled unidirectional CFRP workpiece edge and unidirectional CFRP workpiece edge when milled with Guhring’s new CFRP milling cutter.

Guhring’s solution is a new milling cutter with innovative cutting edge geometry. Two cutting edges are positioned to each other at a helix angle of 25°, with unequally spaced cutting edges at the circumference.

Advantages of this new geometry are no tendency to premature delamination; extremely smooth operation, even with unstable clamping; delamination-free machining; and longer tool life.

Iscar DOVE IQ845 milling line

Iscar’s new IQ845 cutters are indexable face mills carrying the IQ845 SYHU ‘square’ (in fact octagonal) double-sided inserts with 8 cutting edges, four on each side. They feature high-positive cutting edges that contribute greatly to a soft cut and smooth entry into and exit from the component being machined. The inserts feature reinforced cutting edges, wiper flats for high surface finish and unique rake face geometry for optimal chip formation. They are mounted into dovetail shaped pockets, secured by screws, which provides extremely rigid clamping. Taking up to 4.6 mm depth of cut, the new face mills are available in a nominal diameter range of 50-160 mm in both coarse- and fine-pitch configurations. 

Iscar Heli-IQ-Mill triangular inserts with helical cutting edges

Latest version of Iscar’s Helimill insert design is the Heli-IQ-Mill 390 family with an extra helical cutting edge; triangular inserts with three helical cuttingedges, compared with two previously. In addition, the construction of the new inserts is stronger. The new family, with 10 and 15 mm cutting edge lengths, permits productive milling of true 90º shoulders, at lower cost per cutting edge for a variety of milling applications. 

Iscar Heli2000 Chatterfree milling inserts

Iscar’s new Heli2000 insert with ‘chatterfree’ geometry can be mounted on any HM90 E90AD endmill, HM90 F90A face mill, Helimill shell mill or extended flute cutter. Features include asymmetric design with two different cutting edges, reduced chatter to increase tool life, special edge preparation, 10% less power consumption than a regular insert, improved chip evacuation and wide wiper edge to improve surface finish. Stocked grades are IC380 and IC830.

Iscar Helitang T465 tangential face mills

Another Iscar introduction is a modified family of 65° lead angle heavy-duty face mills with tangentially mounted wedge-shaped inserts. The 65° lead angle is a very efficient solution for high metal removal face machining of cast iron and steel components. Using these face mills minimises burrs and edge chipping for cast iron applications.

The inserts have four cutting edges, for up to 19mm depth of cut. 

Available grades are IC830, IC5400, DT7150, IC5100 and IC810, used for steel and cast iron, and grade IC330 for machining stainless steel and high temperature alloys.

Kennametal Mill 4-15 shoulder milling tools and inserts

Demonstrating the excellence of modern insert manufacturing techniques, the new Mill 4-15 shoulder-milling platform from Kennametal employs an innovative double-sided insert design with four cutting edges. Options are available for 90º applications. Each insert has four cutting edges, able to take up to 15mm depth of cut, while a unique cutting edge design assures positive contact through 90º milling and virtually stepless solution for stepping-down applications. An integrated wiper facet is claimed to achieve best-in-class surface finish. 

Mill 4-15 inserts are available precision ground or moulded with corner nose radii from 0.4 to 2.4mm. Cutter body options include screw-on, cylindrical shank endmills, Weldon shank endmills and shell mill cutters with effective internal coolant. 

Komet’s low-vibration face mill

Komet Group presented the hi.aeQ high-performance arbor face-milling cutter at EMO 2013. Design applications are shoulder and face-milling of cast iron workpieces. The nickel-plated body of the new Komet hi.aeQ arbor milling cutter carries Q80 tangential screwed indexable inserts, fitted alternately vertically and horizontally at the tool circumference. In this way each insert provides eight usable cutting edges.

Designed for counterboring and milling operations, the Q80 inserts provide a high level of stability. They are characterised by low vibration and low cutting forces, which reduces power consumption and spindle load. The inserts can be supplied with a PVD or CVD coating. Stocked diameters are 63, 80, 100, 125 and 160mm.

Mitsubishi iMX exchangeable head endmills

The iMX series combines the advantages of both solid carbide and indexable end mills. Huge performance advantages and savings are claimed, especially when long overhang applications are required. The high cost of extra-long solid carbide endmills is more than balanced by the use of exchangeable heads.

The ‘world first’ (according to Mitsubishi research) feature of the carbide head and carbide holder gives security and rigidity close to that of a solid type carbide endmill. This is because the taper and end clamping faces of the head and holder, are both solid carbide, only the threaded part being steel. 

Benefits of this secure and accurate clamping are greater efficiency, improved accuracy and reliability. 

Other tools with a carbide head to carbide clamping interface are usually constructed with a part carbide section brazed to a steel shank. This method has inherent weaknesses at the joint when compared to solid sintered carbide.

Primary application areas are the machining of titanium alloys, heat-resistant alloys such as Inconel and high-duty steels. Each head type has irregular helical flutes for vibration control and the 4-flute corner radius type incorporates through coolant holes. Variable-helix iMX heads are stocked in 12 different geometries.

A key factor in the new system is the Smart Miracle coated carbide grade EP7020. The superfine carbide substrate has a newly developed aluminium chromium nitride Smart Miracle coating which has also been given a smoothing treatment, resulting in better machined surfaces, reduced cutting resistance and improved swarf removal.

Seco Disc Milling Cutter 335.25 for larger grooves

Seco disc milling cutters are used in many different ways, for circlip grooves from 2.25 mm width up to 31 mm, with fixed or adjustable pocket seats, multi-functional for slot, square shoulder and face milling, copy and T-slot milling or for the production of undercuts. The disc milling cutter 335.25 for large groove widths up to 26 mm is the latest member of Seco’s family of disc milling cutters, the most comprehensive range on the market. 

The multi-edged XNHQ1407 inserts with corner radii from 0.8 to 6 mm offer 4 effective cutting edges each with an integrated secondary cutting edge in order to achieve smooth slot walls. Thisresults in optimal surface finish and considerably reduced cost per cutting edge. Furthermore, the thick, strong inserts ensure high stability and process security. Thanks to the optimised design of the cutting edge the milling cutter provides a soft cutting action and achieves a flat bottom to the groove. The disc milling cutter 335.25 is well-suited for various operations in the most different materials due to the large range of corner radii and suitable cutting grades. 

The 335.25 is available with fixed pockets as well as an adjustable version for cutting widths from 21 to 26 mm in the diameter range from 125 to 315 mm.

Walter Porcupine’s ‘unyielding spines’

After the successful market launch of the F5041 and F5141 shoulder mills, Walter introduced the F5138, the first ‘porcupine’ cutter in its Blaxx design. A special feature is the distinctive, specially treated glossy black surface which provides highly effective protection from corrosion and wear. As with other Walter shoulder mills, the F5138 porcupine cutter provides feed rates said to far exceed those of conventional examples from this tool class whether machining steel, stainless steel, non-ferrous metals or cast iron.

Four-edged, tangential indexable inserts are made of Tiger•tec Silver high-performance cutting materials, claiming a ‘unique’ (but unspecified) hardness/toughness ratio. Grades are WKP25S and WKP35S for steel and cast iron, and WSM35S and WSP45S for stainless steel and materials with difficult cutting properties. Diameter range of the F5138 porcupine cutter is 40 to 80mm with two different cutting lengths per diameter.

Part two - turning, grooving and parting

Part four - drilling, tapping and reaming