Final Report Summary - IDEA (Integrated design and product development for the eco-efficient production of low-weight aeroplane equipment) The project IDEA aimed at substituting aircraft components manufactured from aluminium or other materials by cast magnesium parts. Integration of Mg alloys into the aerospace will lead to breakthroughs, which will reduce the airplane's weight, improve the noise damping and reduce the fuel consumption and air pollution.Nowadays approximately 20 Mg-casting alloys are available; however, more than 97 % of the castings are made of AZ91, AM50 (or AM60) and WE54 or AS21 (or other sand cast alloys for specific applications). Thus, there is a need to increase the number of Mg-alloys available for aerospace applications with their specific requirements to strength, damping properties, corrosion resistance etc.The technical objectives of the project were:1. To develop new lightweight Mg-alloys, which fulfil the requirements for castability, corrosion resistance and mechanical properties of the cast components.2. To determine corrosion rates, analyse diffusion processes and develop conducting and non-conducting coatings for the new Mg-alloys.3. To optimise the most appropriate casting processes (investment casting, sand casting, gravity die-casting, but also high pressure die-casting) for Mg alloys.4. To develop and use specific simulation tools for determination of local mechanical part properties and virtual standard tests of cast components. 5. To prepare a design manual for cast magnesium components in aeronautic applications. The manual is aimed to be a guide for aviation designers to select convenient Mg-alloys and production methods for convenient aircraft components.6. To produce demonstrator castings for typical thick-walled and thin-walled aerospace applications.To achieve the above objective the consortium worked in the following main areas:- Alloy developmentOnce the requirements were known new alloys for gravity casting and high-pressure die-casting were developed. High-pressure die-casting was included although the process is not appropriate for production of high performance small series parts. Nevertheless, it should be pointed out that not only aircraft parts are in the focus of weight reduction but also movable equipment like trolleys that do not need to fulfil high requirements and may be produced in larger series. New alloys were first developed and after thorough testing on laboratory scale four alloys were selected for further tests in industrial environment. Two of them were finally chosen for prototype production. - Corrosion protection and surface technologyPart of the tests and developments was dedicated to corrosion protection. Corrosion properties of the new alloys were determined and compared to those of commercial magnesium alloys. In parallel, new coatings were developed and compared to commercial coatings. - Casting technology and simulationSand casting, investment casting, gravity die-casting and high-pressure die-casting (HPDC) processes were considered in IDEA. The overall goal was to improve these processes to enable production of thin-walled components with commercial and new magnesium alloys. Since numerical simulation should play a major role in the design of running and feeding systems a substantial amount of effort was allocated to measurements and experiments, which allowed determining material properties and casting properties as well as development and verification of simulation models. Further efforts were allocated to: - development of new non-reactive shell mould material for investment casting of magnesium; - determination of a minimum amount of SF6 gas for flushing of the investment moulds; - development of alternative inhibiting substance for investment casting and determination of its optimum use. Exploitation Project achievements and knowledge gained during the project were gathered, organised and made available in form of a design manual for aviation engineers. End use and prototypingThe clamp keeping the whole project together was given by the end user, I.A.I. and supported by the advisory group of experts from aviation industry, supply industry and research. In the beginning of the project components were selected, which finally should be cast with the new magnesium alloys. The requirements to the properties of these parts allowed defining the requirements to the new alloys. At the end of the project, the prototypes were produced and evaluated by the end user.These objectives were achieved by developing 11 new magnesium alloys for gravity casting and high-pressure die-casting. Prototype castings have been produced to demonstrate the potential of the new alloys. Furthermore, the consortium developed new efficient coatings for magnesium parts, an alternative inhibiting substance for investment casting, computer models for prediction of microstructure, defects and mechanical properties of magnesium castings, and a design manual for magnesium castings in aircrafts.Two demonstrator castings were developed: the housing and the pedal. The housing is a semi structural part. A box in which motion transfer mechanism from the cockpit to tail through pressure bulkhead is located. It is attached to the pressure bulkhead and is part of the flight control system. The rudder pedal transmits pilot control inputs to yaw and brake control.The project yielded significant results. A summary of conclusions and prospects regarding aerospace applications is seen below:- The new gravity Mg-alloy (MRI207S) fulfils aerospace requirements, which are those of commonly used aluminium A357 alloy.- The pedals were successfully produced by investment casting and gravity die casting. All the pedals passed load limit and endurance tests.- MRI 207S casting technology for the housing did not succeed to produce sound castings according to aircraft requirements as defined by I.A.I. However, it looks like the gap for achieving the goal is very close and reachable.- Considering the current state of the art, sand casting is the preferred potential technology for the housing. However, further process development is required in order to obtain sound castings.- MRI 207S investment casting process requires significant improvement in order to realise the potential of the process for the production of the housing, but this technology has a high potential due to the achieved surface quality.- HPDC is not suitable for structural aircraft parts due to low mechanical properties, porosity, and tooling costs.- Corrosion tests for the various coatings and alloys revealed that AZ91E with phosphate conversion coating and epoxy primer is the most corrosion resistant. No corrosion signs were detected after 1 000 hours in salt spray.- MRI 207S anodised and primed with epoxy primer showed corrosion signs in the scratch region after 672 hours in salt spray. Other areas were attacked after 840 hours.- All tested Mg-alloys passed the flammability test.- MRI207S exhibits higher mechanical properties than AZ91E. However, it failed in full fatigue test due to micro-cracks, which can be overcome with appropriate casting technology. Related documents Final Report - IDEA (Integrated design and product development for the eco-efficient production of low-weight aeroplane equipment)
