The edge on cutting aerospace composites

With the increasing use of high-performance composites, such as carbon fiber-reinforced plastics in aerospace in recent years, machinists are continuing to devise the best way of cutting them.

Composites present unique machining challenges compared to metals. Carbon reinforcement fibers are abrasive, shortening tool life. Machining composites often results in dust, rather than chips, that carries little heat away, causing the matrix to melt from overheating. Delamination and burrs are additional challenges.

When cutting or drilling carbon-fiber reinforced plastics (CFRP), the process generally requires less power and uses higher spindle speeds compared to many metals. These factors lead to increased emphasis on the tool. Its design is critical to success- a sharp edge to shear individual fibers that wears well against the abrasive fibers. Additionally, in aerospace it is common to drill layered “stacks” composed of CFRP combined with titanium or aluminum. Designing a single tool optimized for layered stacks presents its own challenge.