WP7: in-situ and ex-situ repairs of aeronautical components: realization

Lead by: EADS
Participating partners: POLIMI, VN, TWI, NAU KHAI, AVIO, EADS, EADS-CASA, IMPACT, IBERIA
Duration: November 2014 – May 2016 (M18-M36)

Overview: Challenges and current SoA

Current repair actions and repair procedures are carried out on aeronautical parts using different coating techniques. In case of thermal spraying these repair operations can be only carried out when the component is demounted from the aircraft and transferred to a repair shop. So this can only be achieved if the par is able to be demounted with low effort. In the case of larger parts that can be demounted only by use of larger effort tis is costly and time consuming. Therefore a new approach would be an in-situ repair on aircraft without any demounting. This can only be achieved with a newly to developed mobile cold spray apparatus in this project

Main Objectives

The research conducted in WP7 is strongly based on the work performed by the previous WPs. The activities will seek to define and prepare the components and repair characteristics for both in-situ and ex-situ applications. In overall, WP7 aims at validating the reliability of the repair process. This will also look into realization of specimens necessary for repair validation. In the end, post-deposition treatments will be carried out following specific procedure of selected components. Thus a precise definition of the work and the way how to accomplish is necessary and a repair validation is carried out before the procedure can be applied.

Related Activities

Task 1: Definition of components and required repair characteristics

Starting from the chart defined during the roadmap of the components, the components and repair must be selected by the aeronautic companies. Similarly, the repair process designed by the cold spray performers for all Al, Mg and Ti alloy repairs, needs to also be selected. These will take into account the specific requirements for the repaired parts and the results coming from the experimental studies on specimens carried out in WP5 and WP6. It will be also defined if the component is devoted to in-situ and/or ex-situ repair. The characterisation tests necessary for the validation (i.e. ASTM-C633, TCT, etc.) will be suggested and then, after approval or modification, approved.

Task 2: Component preparation

The component must be prepared before deposition in order to allow the optimised processability by Cold Spray. The features coming from process optimisation carried out in WP5 and WP6 will be considered. Machining could be required in order to prepare a proper geometric feature to allow Cold Spray. Cleaning and/or further preparation, such as sandblasting, could be also required as final step of preparation. Aeronautic companies will preferentially prepare the components following the traditional machining used in mass production and following the requirements defined after the tests on specimens. Further operations of surface preparation (cleaning, sandblasting, etc.) could be performed at properly equipped RTD sites.

Task 3: Repair realization and reliability tests (ex-situ)

The realization of the Cold Spray repair following the deposition protocols defined during WP5 and WP6 will be carried out by cold spray performers depending on specific process and components. The component will be mounted and the deposition strategy (robot moving, coating thickness, thickness/deposition pass, deposition angle, etc.) defined in a detailed protocol before deposition. The repair processes will be carried out in different sites with the same equipments and procedures, in order to give further reliability to the process. Some specimens for process validation will be also deposited in the same deposition run in order to perform the required characterisation tests, following the defined guidelines.

Task 4: Repair realization and reliability tests (in-situ)

The new portable Cold Spray unit developed will be used in this task. Realization of the Cold Spray repair following the deposition protocols defined during WP5 and WP6 will be carried out. The repair operation could be carried out both at laboratory sites and/or directly at the aeronautical companies sites, thus moving the portable Cold Spray unit and key personnel. Some specimens for process validation will be also deposited in the same deposition run in order to perform the required characterisation tests according to the defined guidelines. Commercially available Spraying System (Dymet 403) could be used to give a comparison between the performances obtained with the new system with the actual state of art available systems.

Task 5: Component post-deposition treatments

Post- deposition treatments will be finally carried out. Thermal treatments could be required (i.e. in the repair of castings) as well machining and finishing of the components. Further surface treatments such as anodic protection, thin film deposition, could be also performed following the procedures currently applied in the production of each specific component. Aeronautic companies generally could perform the treatments following the standard procedures for the specific, having an immediate comparison between repaired and new non-damaged components.

Expected Results beyond the SoA

WP7 research will lead in component definition, selection and preparation. Accordingly, repaired components and process report for both in-situ and ex-situ applications will be able to be defined. The research will also allow the realization of final treatments (post-deposition thermal, machining, finishing, etc.) and the definition of a full procedure for the repair of each component: In the end, the demonstrator and results will be selected and devoted to dissemination activities.


 

The activities related to the CORSAIR research are being organized in the following Work Packages (WPs):