In aerospace, working with lightweight composite materials is more than common. Standard tools and methods designed for working metal just won’t cut it when it comes to manufacturing aerospace components made for these specific materials.
Carbon-fiber material is also very abrasive, so with a typical cutting tool that may last for several hundred holes on a metal such as aluminum, you may only get about 25 holes on Carbon-fiber.
For example, the Boeing 787 is made of about 50 percent CFRP and uses 20 to 25 percent less jet fuel than a comparable aluminum plane. The composite fuselage is manufactured in complete round barrel sections, rather than in segments and pieces. However, constructing such a plane leads to challenges in the machining development process.
Tools for Milling and Drilling Composites
To last longer, machine tools for Carbon-fiber must be either veined polycrystalline diamond (PCD) or coated with a layer of submicron diamond particles, which makes these tools more costly than your traditional tool.
Another consideration is the cost of tool changes. Tooling material is not the only difference for Carbon-fiber machining. Unlike metals, the two most challenging problems in milling and drilling Carbon-fiber are fibers in the hole and delamination.
When it comes down to it, the correct way to measure the cost of producing a part isn’t by the cost per tool, but instead the cost per hole drilled. Tools designed for Carbon-fiber machining have a very different set of geometries, depending on the process and the application.
Stacking Carbon-fiber With Metals
Special Carbon-fiber tools won’t often work in typical metal work which is a complication on it’s own. Usually, composites are stacked with other materials- for an example, you may be drilling through Carbon-fiber and suddenly hit a layer of aluminum or titanium, and the tool must be fit enough to produce a single hole
When it comes to machining Carbon-fiber stacked with metal sheets in the aerospace industry, one of the biggest challenges is that a lot of these airplane components can’t be exposed to cutting fluid for cooling and carrying away chips.
There are a few different things that people try to try and accommodate the different layers, such as adding a chip breaker for an aluminum sheet, to prevent long chip strings from tearing up the fibers and making the hole too large
If the holes will be drilled with automatic drilling units, some of the newer ones have programmable RPM and feed rates, so you can drill the Carbon-fiber in a stack at one speed and feed and as soon as you hit the titanium, you may be able to change the cutting data, and optimize it for each layer.
Learn more about the tooling within specific industries and their dynamics by visiting our website or contacting us for any inquiries at (905) 664-9531.
