RAPOLAC was initiated in 2005 by the Advanced Manufacturing Research Centre (AMRC) at the University of Sheffield in collaboration with seven partners from across Europe. It was funded between February 2007 and July 2010 by the European 6th Framework Aeronautics and Space Programme which aimed to strengthen European competitiveness in manufacturing.
RAPOLAC focussed on the Shaped Metal Deposition (SMD) process which is ideal for use in prototype production as well as in manufacturing, eliminating the need for tooling and shortening development lead-times. It uses no tooling and has low to zero harmful emissions.
The main objective of RAPOLAC was to develop the SMD process for use in production, to the point where it can reliably and repeatedly produce component geometries. This meant finding stable parameter windows which would produce material with known properties, developing a controller so that the cell could be left unattended and presenting a business case for SMD..
Research strategy
The success of SMD technology within aerospace relies on producing equivalent or better material propoerties with increased cost-effectiveness.
Research was carried out to discover the optimal welding parameters (current, travel speed and wire speed for example) for a variety of aerospace materials. By varying these parameters, it is possible to produce parts with tailored microstructures and material properties.
To achieve these goals, RAPOLAC had 3 main research strands:
- Process modelling at micro- and macro- scales;
- Investigation of part microstructure and material properties;
- Process control;
with the exploitation of the results leading to another 2 strands:
- Integration of the process controller;
- Development of a business case for SMEs;
The main outputs of RAPOLAC were:
- Stable parameter sets for the materials chosen;
- Known material properties for a given parameter window and part geometry;
- A prototype control system integrated with the main SMD cell;
- A cost and environmental comparison of SMD and traditional production processes;
- A business plan for SMD;
- Example parts with different geometries for dissemination purposes;
Scientific and technical objectives:
- Reduction of 60% in the lead-time necessary to produce new parts, through the elimination of tooling and the use of SMD parts as manufacturing prototypes, particularly affecting SMEs working on small batches of parts;
- Reduction in the cost of manufacturing final products by 40%, through the reduction in raw material usage, finish machining and machining products and the elimination of tooling;
- Reduction in the cost of inventory held of 90%, since the only inventory held is wire. Parts are stored as programs and then built to order.