Fraunhofer study evaluates cost-saving potential of BLISK method

With the BLISK study results, the researchers hope to increase developing advanced manufacturing processes for serial production.

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Researchers at the Fraunhofer Institute for Production Technology (Fraunhofer IPT; Aachen, Germany) and collaborators have analyzed different process chains for blade integrated disk (BLISK) manufacturing, and—in a benchmarking study—identified significant cost-saving potential in using the BLISK method. With these study results, the researchers hope to increase effort for developing advanced manufacturing processes for serial production.

Manufacturers of aircraft engines have a major influence on increasing resource efficiency in air transportation by using new technologies to realize innovative engine concepts. Integrated design as established with BLISK in past years leads to more complex geometries and manufacturing challenges. Additionally, the use of new materials requires continuous development of machining processes. To ensure sustainable cost efficiency of manufacturing processes, the application potential of relevant technologies has to be monitored continuously and be benchmarked in terms of productivity and manufacturing cost.

So, the researchers compared different process chains from an economic and technological point of view, along with their colleagues from the WZL tool machine laboratory at RWTH Aachen and EMAG ECM GmbH. "We looked at a total of seven different process chains based on a BLISK made of nickel," explains Daniel Heinen, manager of the business unit Turbomachinery at Fraunhofer IPT. To achieve an objective comparison, the research team looked at a few promising alternatives alongside conventional milling from a solid block: electrochemical machining (ECM), water-jet machining, and wire-based laser metal deposition, a manufacturing process for layer-wise build-up of the blades. In each of these processes, however, the surfaces have to be reworked—for example, by automated polishing or by precise electrochemical machining (PECM).

Content Dam Ils Online Articles 2016 05 Pi16 Ila Ipt Significant Web
A new study compares different process chains in BLISK manufacturing from an economic and technological point of view. (©Fraunhofer IPT)

Specially developed software made it possible to calculate the resource requirements of the different manufacturing process chains and technologies in a comparable way. The researchers recorded all the information for each process chain: economic and environmental constraints (such as the cost of the machinery), production times, the expense of CAD/CAM programming, and the number of components to be manufactured, allowing not only the production cost to be identified, but also the primary energy demand and the CO2 balance.

Their comparison shows that production costs could be halved by conducting idealized or innovative process chains, Heinen concludes. A large portion are fixed machine costs--depending on the process chain, these can vary between 20 and 70%. The assessment methodology is independent of the component shape, and can be easily adapted to different geometries, manufacturing processes, and changes in volumes. By studying the individual processes technologically, the researchers can also identify resource requirements for manufacturing alternative component geometries more specifically, deduce dependencies of various production processes, and therefore help companies make a decision when it comes to choosing the right process.

The researchers will be presenting their results at the ILA Berlin Air Show 2016, set to take place June 1-4 (Hall 4, Stand 202).

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