AMP - Advanced Manufacturing Park

Unique point geometry makes Dormer's new solid carbide drill perfect for machining composite materials.

As use of composite materials within many industries increases, new machining challenges arise. Although composite materials have many advantages, including excellent strength-to-weight ratio and corrosion resistance, they are more brittle than metal.

"Machining of composite materials can cause problems such as delamination between layers at a hole entry or exit, fraying, hole erosion and splintering – additional hole quality parameters," says David Goulbourne, development manager for drills at Dormer.

The task calls for specially developed tools, such as Dormer's new solid carbide drill for machining composite materials. The new Dormer drill is designed for use in Polymer Matrix Composites (PMCs) - also known as Fibre-Reinforced Polymers (FRPs) - and works equally well in Carbon Fibre Reinforced Polymers (CFRPs) and Glass Fibre Reinforced Polymers (GFRPs).

Dormer developed the drill in cooperation with the University of Sheffield's Advanced Manufacturing Research Centre (AMRC) with Boeing in the UK, based at Rotherham's Advanced Manufacturing Park (AMP). "We had a knowledge transfer partnership with AMRC, which is a two year program where a post graduate works on a specific project," explains Mr Goulbourne. "The project was ultimately focused on drilling composite and composite stack materials, investigated the machining properties of the material. Various prototypes were analysed before we came up with the final design."

Dormer's new composite drill has a unique, patented point geometry that reduces thrust and torque, lowers cutting temperatures and minimises delamination and splintering at hole exits. There is also an internal coolant option available for wet machining.

The drill was launched in September 2008 and comes in a range of 2.38 to 20 millimeters in diameter.

Already common in the aerospace and automotive industries, Mr Goulbourne expects the market demand for composite drills to increase further as use of composite materials becomes more widespread.

To stay on top of its game, Dormer has an ongoing partnership with the AMRC Composite Centre, also at the AMP. The centre is AMRC’s research, design, manufacturing and technology transfer centre for composites developed for general manufacturing and aerospace applications.

"The AMRC has knowledge and understanding of composite materials, which provides us with an insight into the materials and their machinability," says Mr Goulbourne. "The partnership allows us to be involved in the ongoing projects and learn more about composite materials and the new and innovative processing methods being developed for industry."

Article from D.World reproduced with kind permission of Dormer Tools