Engines

Industrial 3D printing of engine components

EOS industrial 3D printing enables cost-effective production of functional engine parts with complex geometries and defined characteristics – even in small production runs.

The benefits of Additive Manufacturing (AM / industrial 3D printing) come to the fore in the production of engine and turbine parts, even for small batch sizes. Functional parts with demanding geometries and defined aerodynamic or fluid-dynamics properties can be manufactured quickly and cost-effectively using EOS laser sintering equipment. That includes fuel systems, guide vanes and turbine blades, add-on systems and special heat protection components. Even extremely complex components made from high-strength material, which may c

EOS Additive Manufacturing technology – Engine components best-practice examples

Aerospace: Vectoflow – Additive Manufacturing of probes for measuring speed and temperature in turbo engines

Flow measurement probes from Vectoflow – robust than

EOS Krailling
Bauteil
Foto: Tobias Hase

ks to additive manufacturing and EOS

Extremely rigid and durable: this compact flow measurement probe was made in one piece using industrial 3D printing. (source: EOS GmbH, Vectoflow)

Flow measurement probes are the components responsible for gauging the speed and angle of attack of an airflow and are used in particular in aircraft and turbo-machinery design. The speed and angle of attack are determined from the inflowing air. While they may seem relatively small and fragile, these systems have to withstand extreme stresses and continue to function reliably at all times. Vectoflow specialises in developing and manufacturing complex flow measurement probes. It uses EOS additive manufacturing technology to achieve an ideal design with maximum endurance.

Challenge

Speed is a major factors for aircraft – firstly to give it its decisive advantage over other forms of transport and secondly, it is a critical factor, since if the speed is too low, the airflow can stop abruptly, causing the aircraft to crash. Too much speed, on the other hand, places too much stress on the components. So-called flow measurement probes are used in aviation in order to constantly measure the relevant speeds. As the air flows through them, the speed is determined based on the pressure. This might, for example, be the flight/air speed or the speed at which air flows through the engines, thus providing propulsion.

Considering the high Mach numbers that are frequently encountered nowadays in both subsonic and supersonic ranges, it is of no doubt that the probes are subjected to severe stress. This is all the more so when functionality has to be guaranteed at large angles of attack, i.e. when the nose of the aircraft points sharply upwards or downwards. High forces and irregular air inflows also occur in certain installation configurations in a jet engine, for example when the probes are located at an angle to the airflow. This is where our Kiel probes, an enhanced development based on traditional flow measurement probes, are a solution. They enable accurate measurements to be taken, for example, during extreme flying manoeuvres or when engines are in a banked position. However, the stresses on the component then increase even further. This is especially the case in the engine, due to the higher thermal loads.

Vectoflow specialises in developing such probes. Right from the start, the specialist team has used additive manufacturing to meet the aforementioned challenges. One special case shows just how great the potential of technology is. The engineers were given the task of producing a group of probes with a particularly aerodynamic designed – a so-called rake. In plain terms, this meant having to produce instruments in a very small and optimised form in order not to disrupt the airflow. At the same time, they had to be able to withstand temperatures of 1,000 degrees Celsius over prolonged periods.

 

Solution

“Our customer, a European research company in the aerospace industry, experienced ongoing problems with probes fracturing because they were made up of multiple parts, which made them unstable. We manufacture our probes in a single piece in order to avoid this type of problem,” explains Katharina Kreitz, Engineer and Director at Vectoflow GmbH. “Additive manufacturing allows us to produce Kiel probes in a single piece, and the special Kiel architecture is only possible using EOS technology. This enables us to implement special functionally integrated designs and attain very small channel and overall sizes.”

When modelling the components, Vectoflow also attaches great importance to minimizing the number of possible disruptive factors and their effects, for example the development of undesirable secondary noise, as acoustics measurement was also part of the remit in this case. The engineers also found effective solutions relating to thermal load capacity thanks to the nature of the layered production with the EOS M 290. The thermal elements measure the temperature of the respective measuring units. The nickel-chromium alloy is even able to withstand high temperatures of up to the required 1,000 degrees Celsius and continue to be fully functional at twice the speed of sound.

Vectoflow also subjected the components to extensive post-production treatment, to optimize the product quality. Specially developed processes give the probes their extremely smooth surfaces and perfect finish. This optimises the aerodynamic quality of the probe such that their functions – measuring pressures and temperatures in the boundary layer of the air flowing from the jet engine – are not impaired.

 

Results

The customer was impressed with the Vectoflow team’s approach, as Katharina Kreitz confirms, “We received very positive feedback. Unlike probes manufactured using the traditional machining process, our sample was impressively robust. Our component is 150 per cent more rigid than conventionally made parts. Moreover, the extremely low thickness, together with the improved aerodynamic design and post-treatment played a major role in allowing the user to obtain very precise measurements.” Formerly frequent component fracturing is now a thing of the past.

And there are further benefits too. For example, the user is now able to enjoy significantly extended component maintenance intervals, and he can perform any work required with the part in situ, which depending on where the part is installed, can save days. This factor has an immediate positive effect on costs and reflects the considerable robustness and high level of safety. What is more, additive manufacturing makes it possible to achieve short production lead times and in turn, rapid delivery. Vectoflow was able to cut its overall production time – from the initial draft to the finished part – to about one third of time it originally needed.

Once again, additive manufacturing shows what it is capable of – maximum flexibility in design, size and material, coupled with fast production and delivery, resulting in precise and reliable components with a long service life. This makes the process ideal for use in aerospace engineering, where maximum safety standards go hand in hand with extreme stresses – at the supersonic speeds.

 

Kiel tubes are used to measure the total pressure in the engine. (source: Vectoflow)

“Our team has many years of experience in fluid-dynamic development as well as in the industry. We are driven by an entrepreneurial spirit that results in the continuous improvement and expansion of our product range, with innovative production methods playing a key role. We are absolutely convinced by EOS technology. It is revolutionary.”

Katharina Kreitz, Vectoflow GmbH

 

Short profile

Vectoflow GmbH is a company operating in the field of fluid-dynamic metrology engineering. Its combination of innovative processes enables it to supply measuring technology in as yet unparalleled quality.

 

 

 

 

Aerospace: EADS and EOS – Study demonstrates savings potential for DMLS in the aerospace industry

Joint EADS Innovation Works (IW) and EOS study demonstrates savings potential for manufacturing in the aerospace industry

Graphic of the conventional design of the assessed steel cast bracket (left) and titanium bracket with optimised topology made by using DMLS technology (Source: EADS)

Graphic of the conventional design of the assessed steel cast bracket (left) and titanium bracket with optimised topology made by using DMLS technology (Source: EADS)

Over the last 40 years aviation’s challenge has shifted from getting airborne, easily and safely, to providing a more sustainable and cost-efficient flying experience. Where Daedalus and Icarus used nothing more than feathers and wax to realize the dream of flight, the design and construction of modern aircraft requires highly developed methods and technologies to meet its challenges.

 

EADS IW, EADS’ Research and Technology organisation, is always investigating new ways for improving manufacturing processes. One of the most recent target areas in this field is the use of Direct Metal Laser Sintering (DMLS), a technology that has been used by EADS IW to research the benefits of optimised design and general production sustainability, by using DMLS to manufacture demonstrators of aerospace parts, including an Airbus nacelle hinge bracket.

 

 

Challenge

Set forth in the EADS vision 2020 is the group’s desire to be geared- up for the challenges of the 21st century. With the challenge of the environment being a key driver, sustainability and a reduction in costs of the group’s manufacturing operations and operational phase of its products underlies the group’s research. EADS IW as a customer and EOS as a technology supplier for DMLS solutions created a lifecycle cooperation in order to gain a better understanding of particular industry requirements and get an overview of the EOS technology’s performance in the areas of quality, sustainability and environmental criteria.

 

As quality, costs and environmental effects play a major role in the decision-making process for design and manufacturing

solutions, EADS IW defined new Technology Readiness Level (TRL) criteria focusing on sustainability. Indeed, aerospace Research and Technology (R&T) at EADS must pass nine TRL processes before a technology can be qualified for use in production. For each TRL review, a technology’s level of maturity is evaluated in terms of performance, engineering, manu- facturing, operational readiness, as well as value and risk. For each of these criteria, new components must out-perform existing ones.

 

The results were expected to show reduced CO2 emissions and higher energy and raw material efficiency as well as optimised recycling. When analysing energy consumption, the company’s investigation must include not only the production phase, but also aspects such as the sourcing and transportation of raw materials, argon consumption for the atomization process of the metal powder material, and the overall waste produced during the atomization process.

 

Solution

A Streamline Life Cycle Assessment (SLCA) performed by EADS IW highlighted, amongst other things, the potential cost and sustainability benefits of DMLS technology during the operational phase in the re-design of Airbus A320 nacelle hinge brack- ets. EADS IW’s data was backed-up by test results from EOS, and in an additional step, by test results from a raw material (powder) supplier – a truly unique approach. Together the companies enriched the lifecycle information: the new brackets were to be lighter in order to significantly reduce energy consumption over their lifetime.

 

In the first step, cast steel nacelle hinge brackets were compared to an additively manufactured (AM) one with optimised titanium design by measuring the energy consumption over the whole lifecycle. The technology turned out to be a good fit for the design optimization of the nacelle hinge brackets as for this application the operational phase is typically 100 times more important than the static phases (e.g. manufacturing of the part). By using the optimised design, energy consumption over the whole lifecycle (including manufacturing and operational phase) of the brackets was lowered by almost 40 %, despite the fact that during the manufacturing phase the EOS technology uses significantly more energy.

In the next step, these ‘static phases’ were evaluated. The manufacturing process of one part was compared for the EADS application in titanium with optimised design, built with rapid investment casting and on an EOS platform. The topology of the component has been optimized with software from Altair. The energy consumption for the production of the bracket, including raw material production, manufacturing process and end-of-life is slightly smaller when moving from rapid investment casting to the EOS platform. The advantage of the EOS technology: the process itself uses only the material that is really needed to build the application. Thus the consumption of raw material can be reduced by up to 75 %.

 

Results

It is important to note that this study focused on a one-part comparison between the DMLS and a rapid investment casting manufacturing process and that the question of scalability is yet to be addressed. However, by working together with partners over the whole lifecycle the study produced some impressive upshots: the optimised design of the engine cowling hinge allowed EADS and EOS to demonstrate the potential to reduce weight per plane by approximately 10 kg –

a noteworthy figure in aviation where every kilo counts. CO2 emissions of the door hinges were reduced by almost 40 % over

the whole lifecycle by optimising the design, and consumption of raw materials was reduced by 25 % compared to rapid investment casting.

 

“DMLS has demonstrated a number of benefits, as it can support the optimisation of design and enable subsequent manufacture in low volume production. In general, the joint study revealed that DMLS has the potential to build light, sustainable parts with due regard for the company’s CO2 footprint,” says Jon Meyer at EADS IW. “A key driver of the study was the integrated and transparent cooperation between customer and supplier with an open approach that saw an unprecedented level of information sharing. This transparent collaboration has set the standard for future studies involving the introduction and adoption of new technologies and processes. Even after the first positive results were evident, neither of the parties settled for the outcome, but continued to investigate options for further improvement.”

 

Part of the project’s success was due to their continued striving towards further improvements, evidenced in the swapping of the EOSINT M 270 for an EOSINT M 280 using titanium instead of steel, which led to additional CO2 savings. DMLS has the potential to help make future aircraft lighter, leading to savings in resources which help to meet sustainability goals without compromising on safety.”

 

Further example of improved part design: prototype of a topology optimised Airbus A380 bracket made of stainless steel powder produced via DMLS with conventional bracket behind (Source: EADS).

Further example of improved part design: prototype of a topology optimised Airbus A380 bracket made of stainless steel powder produced via DMLS with conventional bracket behind (Source: EADS).

“We see several advantages in the use of DMLS, mainly concerning freedom of design and ecological aspects. We can optimize structures and integrate dedicated functionality and DMLS can significantly reduce sites’ CO2 footprints as our study with EOS demonstrated.”

 

“Considering ecology and design taken together, optimised structures can also result in reduced CO2 emissions due to weight reduction.

I see tremendous potential in DMLS technology for future aircraft generations, when it comes to both development and manufacturing.

Jon Meyer, ALM Research Team Leader at EADS Innovation Works

 

Short profile

EADS is a global leader in aerospace, defence and related services. In 2011, the Group – comprising Airbus, Astrium, Cassidian and Eurocopter – generated revenues of € 49.1 billion and employed a workforce of over 133,000.

 

Address

EADS Innovation Works

Building 20A1

Golf Course Lane

Filton, Bristol BS34 7QQ (UK)

Aerospace: MTU –  Manufacturing of Engine Components for the Airbus A320neo with EOS Technology

EOS Technology Enables the Cost-Effective Manufacture of Engine Components for the Airbus A320neo

Additive Manufactured borescope bosses from MTU Aero Engines for the high-speed, low-pressure turbine of the Geared Turbo Fan engine PurePower® PW1100G-JM, which will power the A320neo (courtesy of MTU Aero Engines).

Additive Manufactured borescope bosses from MTU Aero Engines for the high-speed, low-pressure turbine of the Geared Turbo Fan engine PurePower® PW1100G-JM, which will power the A320neo (courtesy of MTU Aero Engines).

15 % less fuel consumption – this is the primary benefit that the manufacturer Airbus wants to give customers with its A320neo, a new short- and medium-haul aircraft. Achieving the goal requires, above all, more efficient engines. MTU Aero Engines is a primary supplier to the US engine manufacturer Pratt & Whitney and plays a key role in Airbus reaching its objectives. In order to remain at the forefront of technology, the Munich-based experts in aircraft engines actively supports the use of innovative production processes. Additive Manufacturing plays an important role here, as shown in the manufacture of borescope bosses – access points for inspecting turbines – a product for which MTU relies on EOS technology.

 

Challenge

The aerospace sector is one of the most innovative in the world. Airbus applied for over 380 patents for the design of the A380 alone. New materials and technologies that are suitable for series production have an important role to play in this industry for reasons that include cost, weight and function. Because of this, both manufacturers and suppliers are testing the performance capabilities of Additive Manufacturing processes, by which components are produced when a powder is hardened, layer by layer, using a laser. This method was originally used in the manufacture of prototypes as it allows for the fast production of individual parts. Due to its many advantages, however, the technology has since established itself as a staple in series production.

 

The advantages associated with this process include increased design freedom as well as a wide range of useable raw materials, from extremely light, fire resistant/flame retardant plastics to a variety of metals. Generally, the moment an aircraft takes to the skies, both cost and safety pressures become significant driving forces. It is therefore important to choose the right middle ground when introducing new technologies. MTU Aero Engines, Germany’s leading engine manufacturer, took a strategic step-by-step approach towards the use of Additive Manufacturing.

 

The company currently uses seven EOS machines. “About ten years ago, we began with the manufacture of tools and development components,” says Dr. Karl-Heinz Dusel, Director of Rapid Technologies at MTU. “In order to optimise capacity utilisation and implement our phased plan, we went in search of further areas where we could apply the technology.” The principal challenge consisted of cost and safety considerations on the one hand, and the pursuit of strategic innovation on the other – and each for serial production.

 

Solution

Borescope bosses will be used on the latest generation of engines – the Geared Turbo Fan (GTF) – and they will be manufactured using EOS machines. “At the beginning of the second phase we started to produce components, which replaced existing parts. The borescope bosses for the low-pressure turbines of the A320neo-GTFs fell into this category,” explains Karl-Heinz Dusel. These small add-on components allow technicians to check the condition of turbine blades inside the engine using endoscopes. The parts are mounted to the turbine housing to create an opening for the endoscope, which in the aerospace sector is termed a borescope.

 

Heat resistance and durability are the key characteristics of the nickel-based alloy that was used. This high-quality material achieves the best results demanded by the component, but it is difficult to machine. Fortunately, a problem like this is easily to overcome with Additive Manufacturing. For the first time, MTU is also acts as a producer of raw materials. The company was able to develop a new process chain, which has been approved and integrated into the manufacturing system.

 

The entire manufacturing process is underpinned by a control system specifically developed by MTU. Online monitoring captures each individual production step and layer. In addition, new quality assurance procedures were introduced, such as optical tomography. The German Federal Aviation Authority even certified the EOS machines. In the past, the borescope bosses were cast, or milled from a solid, but the low-pressure turbines for the A320neo’s Geared Turbo Fan are the first turbines to be serially equipped with borescope bosses produced using Additive Manufacturing. Above all, it was the cost advantages of the EOS technology that were the decisive factor, both in the production itself and in the development stages.

 

Results

The strategic approach paid off for MTU, as did the close and positive collaboration with EOS. The series production of the borescope bosses is running successfully. 16 parts per job are envisaged, totalling up to 2,000 parts per year. The savings in percentage terms, compared to conventionally processes, is expected to be in double figures and quality is already at a high level. MTU and EOS are working together to further optimise the finishing for the component, especially the smooth surfaces, with the aim of achieving perfection in the component’s strength.

 

For Dusel, the advantages are clear: “The EOS technology is characterized by its great design freedom and the significantly shortened development, production and delivery times. In addition development and production costs are drastically reduced. Components of lighter weight and greater complexity can be made a reality and production requires less material and minimal tools.”

 

MTU sees a lot of potential for the manufacture of further series components for aero engine construction, such as for bearing housings or the blades for turbines and structure components – which need to meet the highest demands in terms of safety and reliability. MTU’s aim: Within 15 years a significant proportion of components should be manufactured using industrial 3D printing. The EOS technology thus contributes to the competitiveness of the company, which is active in one of the most demanding sectors in the world.

 

“The Additive Manufacturing of borescope bosses for series production has been a great success. Once again this proves MTU’s commitment to innovation leadership. We produce one of the world’s most advanced engines – the Geared Turbo Fan with some of the world’s most advanced processes.”

Dr. Karl-Heinz Dusel, Director of Rapid Technologies at MTU

 

Short Profile

MTU Aero Engines is Germany’s leading engine manufacturer. This long-established company based in Munich has about 9,000 employees. It develops, produces and distributes components for civil and military aircraft engines as well as for gas turbines. The company also advises clients and supervises final engine assembly and servicing.