Drilling CFRP and Non-Ferrous Materials with Micro Tools
Carbon-fibre composites, aluminium and copper each fail micro tools in different ways. This note covers which tool geometry and coating handles each, and what to watch for on delamination.
Non-ferrous materials and composites are easier to cut than hardened steel in terms of force, but they break tools in ways that steel does not. Friction, built-up edge and delamination are the failure modes, and each one has a different fix.
Aluminium
Aluminium abrades carbide quickly because the chip is soft and metallic-bonding. DLC or ZrCN coatings reduce friction and suppress built-up edge, and a generous helix angle lets the chip escape rather than pack. Too many flutes is a common error here — two or four flutes with good clearance is better than six with none.
Copper and brass
The same built-up edge problem, worse in copper because of its thermal conductivity and its tendency to adhere. Reduce speed rather than increasing it, use a coating with low friction, and keep the point geometry sharp enough to cut through the adhesion rather than being dragged into it.
Carbon-fibre reinforced polymer
Delamination is the concern, not tool wear. The fibre is hard and abrasive, the matrix is soft, and the two separate at the tool edge. Control delamination by keeping the point sharp, the speed moderate and the feed steady rather than interrupted. DLC coatings are the standard choice because they reduce the friction that lifts the fibre.
- Sharp, well-defined point geometry — no worn or chipped edge
- Moderate speed and consistent feed; avoid feed interruption
- DLC coating to reduce fibre friction
- Positive chip evacuation — spiral flutes, not straight
- Frequent tool inspection; delamination damage is often on the exit side
Graphite and composites in mould work
Graphite is abrasive and demands a coating that will not bond to the chip. DLC performs well and the tool should be inspected more often than for steel, because wear is gradual rather than sudden.
Send us the composite
Composite layup, resin system and thickness change the picture considerably. If you are unsure, send a sample of the material and we will trial it before proposing a tool.
Does this apply to your part?
Send the drawing and we will tell you, not guess.
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Micro drills from 0.03 mm, in standard, helical, step, left-hand and aluminium-grade geometry. Every entry is a live, shipped configuration.
End mills from 0.1 mm across single and double flute, helical and straight, ball and flat geometry, with aluminium- and acrylic-dedicated lines.
Single and double flute chamfer mills, ball-tip finishing cutters, flat-bottom finishing cutters and extended-reach versions for deep features.
