Periodic Reporting for period 1 - ADDIFLAP (ADDITIVE MANUFACTURING of FLAP TRACKS based on LASER W-DED PROCESS)
Periodo di rendicontazione: 2021-04-01 al 2022-05-31
The environmental challenge (reduction of fuel consumption) for aircraft industry is driving new handicaps in this sector as improvements on fuselage and aircraft engines and light weighting. Indirectly, reduction of maintenance operations has also influence on environmental footprint by reducing the waste parts, oils or greases, etc.
To reduce the weight of the aircraft, the industry is developing a growing proportion of aircraft parts in lightweight materials as titanium alloys, which are generally expensive. Besides the “buy-to-fly” (BTF) ratio (the mass ratio between the raw material used to produce a component and the mass of the component) is 12–25:1 for aircraft titanium products made by traditional manufacturing methods, especially for larger components, raising the scrap material, and thus the environmental impact and the production costs. Additive Manufacturing (AM) is being the alternative manufacturing process to reduce waste material and the production costs, particularly Directed Energy Deposition processes with wire feeding. The Wire Directed Energy Deposition (W-DED) process is becoming a key manufacturing process in aerospace development, mainly due to high deposition rate, the ability to build larger structures and high efficiency in material compared with powder AM technologies.
However, manufacturing of medium-/large-sized metal components is still challenging. W-DED-LB techniques have an important drawback linked to a complex heat management. The implementation of inappropriate building strategies would result in important distortions and residual stresses in the final built component. The implementation of a novel manufacturing methodology able to ensure the quality of the built component is a key issue to overcome. The combination of the manufacturing strategies and the main advantages of coaxial W-DED-LB process proposed in ADDIFLAP will enable to manufacture a low distortion near net shape (NNS) for flap track structure.
On the other hand, surfaces in interacting motion are the foundation of the critical energy-efficiency properties of friction, lubrication and wear behaviour. One of the breakthroughs in tribology is to design solid films with desirable friction and wear properties across the load, speed and temperature ranges to reduce the use of lubricants minimizing the maintenance of the components. Self-lubricating materials based on wear resistant polymers such as PEEK or metal matrix filled with solid lubricating compounds typically MoS2, PTFE, graphite and even more recently graphene have been developed in the last years to avoid using liquid or grease lubricants, being the best choice in more severe conditions.
The ADDIFLAP general aim is the development of a new concept of flap track system by combining a novel flap track support manufactured by Laser Wire Direct Energy Deposition (W-DED-LB) with a new design of carriage system based in sliding pad concept, made using a self-lubricant material. The technology developed in ADDIFLAP will enable the design of a multifunctional flap which combines aileron and high lift functions in one flap body having direct impact on weight reduction. Addition improvement for carriage system based on a sliding pad concept will support the replacement of the actual roller system, reducing the maintenance and the use of greases during the service life of the aircraft.
To reduce the weight of the aircraft, the industry is developing a growing proportion of aircraft parts in lightweight materials as titanium alloys, which are generally expensive. Besides the “buy-to-fly” (BTF) ratio (the mass ratio between the raw material used to produce a component and the mass of the component) is 12–25:1 for aircraft titanium products made by traditional manufacturing methods, especially for larger components, raising the scrap material, and thus the environmental impact and the production costs. Additive Manufacturing (AM) is being the alternative manufacturing process to reduce waste material and the production costs, particularly Directed Energy Deposition processes with wire feeding. The Wire Directed Energy Deposition (W-DED) process is becoming a key manufacturing process in aerospace development, mainly due to high deposition rate, the ability to build larger structures and high efficiency in material compared with powder AM technologies.
However, manufacturing of medium-/large-sized metal components is still challenging. W-DED-LB techniques have an important drawback linked to a complex heat management. The implementation of inappropriate building strategies would result in important distortions and residual stresses in the final built component. The implementation of a novel manufacturing methodology able to ensure the quality of the built component is a key issue to overcome. The combination of the manufacturing strategies and the main advantages of coaxial W-DED-LB process proposed in ADDIFLAP will enable to manufacture a low distortion near net shape (NNS) for flap track structure.
On the other hand, surfaces in interacting motion are the foundation of the critical energy-efficiency properties of friction, lubrication and wear behaviour. One of the breakthroughs in tribology is to design solid films with desirable friction and wear properties across the load, speed and temperature ranges to reduce the use of lubricants minimizing the maintenance of the components. Self-lubricating materials based on wear resistant polymers such as PEEK or metal matrix filled with solid lubricating compounds typically MoS2, PTFE, graphite and even more recently graphene have been developed in the last years to avoid using liquid or grease lubricants, being the best choice in more severe conditions.
The ADDIFLAP general aim is the development of a new concept of flap track system by combining a novel flap track support manufactured by Laser Wire Direct Energy Deposition (W-DED-LB) with a new design of carriage system based in sliding pad concept, made using a self-lubricant material. The technology developed in ADDIFLAP will enable the design of a multifunctional flap which combines aileron and high lift functions in one flap body having direct impact on weight reduction. Addition improvement for carriage system based on a sliding pad concept will support the replacement of the actual roller system, reducing the maintenance and the use of greases during the service life of the aircraft.
To reach the main goal of ADDIFLAP project major activities have been performed up to now on the different WP of the project:
Activities of WP1 have been focussed on the definition of the test plan for coupon test, development of simulation models for W-DED-LB process of Ti6Al4V material and set up of the manufacturing process. Manufacturing strategies were tested and compared with simulation results, and final manufacturing strategy was selected. Finally, the setup of the W-DED-LB process was established including design of inert chamber, clamping tool and optimization of process parameters. Manufacturing of different near net shapes have been performed at small scale demonstrators.
In WP2, activities have been started with the characterization of the deposited material from the near net geometries manufactured in WP1. Those activities are useful to detect manufacturing defects and adjust the trajectories adequately. Dimensional control of the near net shapes has been performed to check the matching between simulation and experimental results. A first approach on metallurgical and mechanical behaviour of deposited material was obtained through coupon tests from deposited material from small near net shapes manufactured. First results on those tests show acceptable mechanical resistance on deposited Ti6Al4V material.
Main objective of the WP3 is to manufacture the flap track demonstrator. Base material for the substrate was acquired and cut to dimensions required for the additive manufacturing of the flap track demonstrator according to the results of the simulation performed in WP 1.
Within the context of WP4, main requirements for determining the wear resistance of the sliding pads have been defined and model experiments with different self-lubricant materials were performed to select the most viable solution for the sliding pad concept. Simulations for design and validation of the maximum contact pressures in the new self-lubricating sliding pads have been performed and sliding pads have been designed.
The activities of WP5 were started studying different loading scenarios for the test rig design, working on the selection of the most feasible solution for the test of the components by simplifying the configuration of loads without compromising the test effectivity.
Dissemination and communication activities have been also performed and several tools have been developed within this reporting period such as the project website or the ADDIFLAP press release at different media. ADDIFLAP KERs have been reviewed and updated, and the draft for IP protection strategy and the exploitation strategy have been addressed.
Activities of WP1 have been focussed on the definition of the test plan for coupon test, development of simulation models for W-DED-LB process of Ti6Al4V material and set up of the manufacturing process. Manufacturing strategies were tested and compared with simulation results, and final manufacturing strategy was selected. Finally, the setup of the W-DED-LB process was established including design of inert chamber, clamping tool and optimization of process parameters. Manufacturing of different near net shapes have been performed at small scale demonstrators.
In WP2, activities have been started with the characterization of the deposited material from the near net geometries manufactured in WP1. Those activities are useful to detect manufacturing defects and adjust the trajectories adequately. Dimensional control of the near net shapes has been performed to check the matching between simulation and experimental results. A first approach on metallurgical and mechanical behaviour of deposited material was obtained through coupon tests from deposited material from small near net shapes manufactured. First results on those tests show acceptable mechanical resistance on deposited Ti6Al4V material.
Main objective of the WP3 is to manufacture the flap track demonstrator. Base material for the substrate was acquired and cut to dimensions required for the additive manufacturing of the flap track demonstrator according to the results of the simulation performed in WP 1.
Within the context of WP4, main requirements for determining the wear resistance of the sliding pads have been defined and model experiments with different self-lubricant materials were performed to select the most viable solution for the sliding pad concept. Simulations for design and validation of the maximum contact pressures in the new self-lubricating sliding pads have been performed and sliding pads have been designed.
The activities of WP5 were started studying different loading scenarios for the test rig design, working on the selection of the most feasible solution for the test of the components by simplifying the configuration of loads without compromising the test effectivity.
Dissemination and communication activities have been also performed and several tools have been developed within this reporting period such as the project website or the ADDIFLAP press release at different media. ADDIFLAP KERs have been reviewed and updated, and the draft for IP protection strategy and the exploitation strategy have been addressed.
Main progresses from the work performed in this period are summarized below:
• Thermo-mechanical approach models base on shrinkage has been developed to simulate distortion in final part. This Finite Element simulations has been conducted to obtain the compensation shape that is the CAD model to balance the distortion according to predictions of shrinkage. The simulation model is able to predict the distortions of large size components enabling the optimization of the manufacturing strategy without large experimental trials.
• Coaxial laser wire DED technology has been demonstrated for manufacturing of large size components in Ti6Al4V under an inert atmosphere. Next step is the validation in a relevant environment with the manufacturing demonstrators of the flap track support according to the ADDIFLAP Manufacturing Procedure enabling to reach the TRL6 of the technology.
• Different self-lubricating concepts have been investigated under realistic contact conditions in model tests. Final solution will be used in the final component test in order to validate the sliding pad concept in a relevant environment.
• Thermo-mechanical approach models base on shrinkage has been developed to simulate distortion in final part. This Finite Element simulations has been conducted to obtain the compensation shape that is the CAD model to balance the distortion according to predictions of shrinkage. The simulation model is able to predict the distortions of large size components enabling the optimization of the manufacturing strategy without large experimental trials.
• Coaxial laser wire DED technology has been demonstrated for manufacturing of large size components in Ti6Al4V under an inert atmosphere. Next step is the validation in a relevant environment with the manufacturing demonstrators of the flap track support according to the ADDIFLAP Manufacturing Procedure enabling to reach the TRL6 of the technology.
• Different self-lubricating concepts have been investigated under realistic contact conditions in model tests. Final solution will be used in the final component test in order to validate the sliding pad concept in a relevant environment.