Holemaking in composites with new PCD-tipped drills


Seco says its new CX1 and CX2 solid polycrystalline diamond-tipped drills will bring increased tool life, productivity and quality to manufacturers machining holes in composite materials. Unlike traditional PCD, vein or dual brazed tip designs, the CX1 and CX2 further prevent delamination and uncut fibres by featuring a solid PCD dome and solid PCD cap, respectively, on a solid carbide drill body. This new PCD technology has also enabled Seco to develop the industry’s first PCD three-flute geometry (CX1) for composite drilling.

Seco claims the CX1 and CX2 drills offer the sharpest and strongest cutting edges currently available. This performance is possible because the new drills use solid PCD tips that can be much sharper than diamond coated drills where the coatings wrap around a drill’s cutting edges and actually create a dulling effect. Other benefits of the new solid PCD tipped drills include high cutting speeds, low friction, good heat transfer, multiple re-sharpening and high process reliability, the company says.

For effective drilling through “plain” composite materials, the third flute on the CX1 provides high levels of stability in the hole as well as decreased vibrations and improved roundness. Furthermore, the dome-shaped tip of the CX1 offers a double-angle geometry. This geometry greatly reduces uncut fibres and delamination in composite-only applications.

Grinding these highly complex types of geometries was previously impossible using conventional brazed or similar such PCD techniques. Plus, the dome cap makes it possible for the drill point to be reconditioned and resharpened up to three times.

The CX2 is a flat geometry drill point for machining stacked composite materials with layers of aluminium or titanium. With this geometry, a PCD cap is used because the drill point is a 180-degree point angle that provides efficient chip breaking and evacuation qualities. This reduces the risk of metal chips damaging the hole when transitioning between layers of metal and composites. As a result, the CX2 keeps the surface finish of the composite intact.

Both the CX1 and CX2 series include a mix of dimensions for holes that range in size from 3.26 to 9.53 (0.125” to 0.375”). Chamfers can also be incorporated into the drill designs to further increase application flexibility.

Seco´s product range includes a complete programme of tools and inserts for turning, milling, drilling, reaming and boring as well as complementary tool holding systems. With more than 25,000 standard products, the company says it is a complete solutions provider for the metal cutting industry and equips machine tools from the spindle down to the cutting edge.


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