Abreakthrough by researchers at the National Laser Centre (NLC) of the Council for Scientific and Industrial Research (CSIR) and technologists at the Aerosud Innovation and Training Centre (ITC) promises to make local aeronautics company Aerosud a world leader in niche aerostructural components manufacture within the next three years. The CSIR and Aerosud are partners in a recently announced project called Aeroswift, funded by the Department of Science and Technology, which has invested R28-million in the programme. Both the CSIR and Aerosud are contributing researchers and other staff, as well as time and funds. Aeroswift aims to locally develop a high-speed, large-volume, laser- based additive manufacturing system to make (initially) titanium parts for the global aerospace industry.
“Additive manufacturing is a very different way of making things,” points out CSIR President CEO Dr Sibusiso Sibisi. “You build the object up by adding material, instead of machining material away. It’s a revolutionary concept. You can make components to exact specifications.” The components are produced, one thin layer at a time, by a laser melting metals or other materials which are in powder form. The result, when applying this manufacturing approach to titanium, is light, strong components that can be in complex shapes.
The breakthrough is that the CSIR NLC/Aerosud consortium has already, in its proof-of-concept trials, achieved processing speeds 8.3 times greater than currently possible using commercial selective laser melting machines. The proof-of-concept trials involved the production of test pieces, which demonstrated the full melting of titanium powders at these high speeds using a patented process. Commercial systems are only capable of producing small parts, no longer than 500 mm. With Aeroswift, the aim is to produce parts as big as 2 m × 0.5 m × 0.5 m.
“I can say that the speed at which technology is developing in the world today is mind-boggling. In some areas, we South Africans are setting the pace. We’ve got real pockets of excellence here,” affirms Deputy Science and technology Minister Derek Hanekom. “But advances in technology are the product of years of perseverance and research. The significance of this can hardly be exaggerated. It’s enhancing the capabilities and competitiveness of the local aerospace industry. There’s a huge opportunity here.”
A key part of Aeroswift is the NLC’s brand-new 5 kW IPG single-mode fibre laser, which will form the heart of the new laser-based additive manufacturing pilot plant. “Now that we have the laser, we can develop the components that will go with it,” explains CSIR NLC laser materials and processing competence area manager Dr Federico Sciammarella. “We’re going to build our own additive manufacturing system around our new laser. This is all designed, but needs to be constructed and tested.” The NLC/Aerosud consortium hopes to have the complete system assembled and tested by the end of 2012 or in early 2013 at the new, second phase of Aerosud’s ITC at the Centurion Aerospace Village. Optimisation and process qualification will then start.
“We are looking for serious cooperation, with OEMs (original-equipment manufacturers – the major global aero- space companies) to be supplying us with target parts,” elucidates Aerosud GM Dr Paul Potgieter. “That’s what is happening. We’re working with the OEMs to develop process qualification. This will probably take three years. Process qualification on new technology like this isn’t easy, nor is it a trivial exercise. The new system will be operational here in 2013 as a pilot plant. Then it will take another year or two for actual process development and quali- fication approval. We hope to start full-scale production and start selling parts to the OEMs in 2015: complex, high-value, low-volume parts in exotic materials (typically titanium) for aerospace – that’s the niche we’re aiming for.”
Even before parts are produced for the OEMs, the system could be making parts for Aerosud’s own Ahrlac aircraft. (Ahrlac is an acronym for advanced high performance light aircraft.) It is hoped that the prototype Ahrlac will make its maiden flight during this year.
“I think the exciting thing about [Aeroswift] is that we have a great public–private partnership,” highlights Sciammarella. “These are the projects that excite people because they have a lot of promise, put South Africa on the map and show we can lead in high technology and advanced manufacturing – and stimulate young people. With additive manufacturing, you can go from design to manufacture in almost real time and if it’s wrong, you can go back and change it easily. That’s the most exciting thing.”