LZH develops fast, precise, and wear-free process for laser drilling CFRP

04 Mar 2024

Holes can be drilled in carbon-reinforced plastics and other composite materials.

Holes can be drilled quickly and automatically in CFRP.

Scientists at Laser Center Hannover (LZH), Germany, have developed an automated process for laser drilling that facilitates the machining of carbon fiber-reinforced plastics (CFRP). They say that this is particularly interesting for applications in lightweight construction and sound insulation.

Composite materials such as carbon fiber-reinforced plastics (CFRP) are excellent for lightweight construction and are used, among other things, in automotive and aircraft construction. In order to simplify the machining of CFRP and sandwich materials, scientists from LZH, together with Invent and KMS Technology Center, have developed an innovative process with associated system setup.

Small diameters

In this process, a laser beam is split into partial beams by specially designed diffractive optical elements, so that it hits multiple locations on the material and generates multiple bores simultaneously. Ideally, says the LZH team, “this can be done with up to 25 partial beams, reducing the drilling time to only a 25th of the original time, resulting in less than a tenth of a second per bore – a value that cannot be achieved with conventional methods even for larger bores.”

With this process, the scientists were able to create bores with diameters ranging from only 1.2 mm to 0.25 mm. This makes them smaller than bores that can currently be implemented with conventional mechanical methods in sandwich and CFRP materials. The use of optomechanics manufactured by KMS Technology Center also enables high flexibility in bore diameter and pattern without the need for tool changes.

Micro-drilling by laser is interesting for the aviation sector.

Construction applications

Micro-drilling with lasers is also interesting for the aviation sector. To reduce aircraft noise emissions, sound-absorbing cladding elements are used to line engines, for example. Such components are often made of CFRP or CFRP sandwich materials and then provided with many small bores over a large area.

Micro-drilling with lasers is suitable for acoustic drilling because it is contactless and therefore force- and wear-free. This eliminates high costs due to tool wear and quality problems due to dull drills. In acoustic tests, project partner Invent evaluated the sound damping properties of the laser-drilled sandwich panels as “very good”.

The project "Micro-drilling of Sandwich Materials: Development of a Laser Process" (miBoS) is funded by the German Federal Ministry of Economics and Climate Protection.

As an independent, non-profit research institute, LZH stands for innovative research, development, and consulting. Supported by the Lower Saxony Ministry of Economics, Transport, Construction and Digitalization, the LZH is dedicated to selflessly promoting applied research in the field of photonics and laser technology. Founded in 1986, it now employs almost 200 employees.