Lead Forensics

3D X-Ray Measurement & Inspection – A Vital Role in Turbine Blade Manufacturi

Jun 1, 2023 | Aerospace, CT Scanning, Manufacturing, Quality & Inspection

Turbine blade manufacturing is one of the most advanced and challenging processes in the aerospace world and is necessary so that the blades can endure tough high-temperature environments and demanding engine cycles.

Further, aircraft engine manufacturers must be able to demonstrate compliance with stringent quality regulations to ensure that these blades will not fail.

Benedikt Krist, of Zeiss Industrial Quality Solutions says, “Turbine blade manufacturing is a complex process with many manual process steps today. There are hundreds of blades in an engine and lots of potential for Computer Tomography [CT] to provide production time savings and costs while reducing wastage.”

Casting of turbine blades involves several steps, beginning with a wax pattern and ceramic core. “At this stage, it is important to check there are no defects – cracks or pores – because they may lead to problems with the cooling in the engine and integrity of the part.

Meanwhile, dimensional checks, like wall thicknesses and profile checks are critical to determine before the expensive metal pouring operation,” says Krist. The inspection method uses the Zeiss Metrotom series of equipment and takes just a few minutes per blade.

After the metal pouring and finishing operations, some critical checks need to be made. “Manufacturers use 2D digital x-ray up to 250Kv to check for any leftover ceramic core inside of the blade cooling passages. Blockages would again result in overheating problems,”

Krist adds. Many manufacturers still use film-based processes, yet Zeiss offers digital radiography and storage of 2D x-ray images which has many benefits in reduced time and costs for performance and storage.

Engine manufacturers are increasingly considering the use of additive manufacturing (AM) as an alternative to casting turbine blades. AM is a faster and more sophisticated process that also brings with it several inspection challenges.

3D CT scanning has emerged as a viable way of inspecting AM parts. It enables fast inspection of the hollow structures and accurate measurement of wall thickness in turbine blades.

ZEISS has a partnership with metal-AM company EOS to develop ways to ensure the quality of AM-metal parts. “We have developed a deep knowledge of AM processes,” says Krist. “We can measure and evaluate AM-parts such as compressor blades, using CT scanning to check for defects and cracks.

“There is a lot of potential to increase the speed of manufacturing things like turbine blades with AM, but it needs advanced inspection technologies like 3D CT scanning for inspection.”

Krist concludes, “We aim to be a metrology solutions provider for aerospace companies – to supply the equipment, the software, the services and the maintenance. We offer one of the broadest portfolios on the market for metrology in aerospace, defence and space, from microscopy and CT to quality inspection production equipment.

“How our products can be used across the turbine blade manufacturing process illustrates how we can help engineers save time and money.”

See the full Aerospace Testing International article.

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The PES Scanning blog provides information and news on the scanning and engineering services we offer. The blog also includes views from our team and information about projects we’ve been working on.