Control techniques have been devised and investigated to minimise distortion, refine grain structures and produce a suitable surface finish. Maintaining the temperature of the metal part while further material is added was expected and has been proved to be of considerable importance for the overall quality of the part.
A 3-D Welding System has been designed and built which is capable of producing metal prototypes directly from 3D CAD with minimal manual intervention. A range of test parts have been successfully produced in mild steel, stainless steel (S92,316) and aluminium alloy (5% Mg) and evaluated.
A powder fusion system has been designed and built that is capable of producing metal prototypes directly from 3D CAD with minimal manual intervention. Using this system parts with increasing geometrical complexity were produced and analysed.
Test pieces have been designed that check the building ability of the Rapid Prototyping systems and the material characteristics of the pieces. Path planning tools have been developed to provide the link from the CAD system to the Rapid Prototyping systems. In this project, slicing and path planning were done directly on the original CAD geometry.
Possible weld bead control systems have been investigated that provide feedback to the welding controller and therefore maintain part quality.
Investigations have shown the ability to produce a variety of weld beads for a different application by altering only one welding variable. The specially produced weld monitoring equipment is now fully functional and operating on the 3D Welding system.
The application of powder layers of equal thickness was chosen as the material source for the powder fusion system because it was more appropriate for massive parts.
Two complementary techniques for the rapid production of metal prototypes will be investigated, one based on multiple pass welding which is suitable for medium to large parts (>50 mm cubed), the second will use laser fusion of metal powders which is suitable for small to medium sized parts (< 1m cubed). The main purpose of this project is to undertake the research and development using these techniques to enable the production of prototype machines to manufacture metal parts within a size envelope of 700x700x700mm and to an accuracy of +/- 0.2 to 0.3 mm.
Main research problems in this project are investigating CAD requirements for the new Rapid Prototyping systems; designing and building the new systems; investigating parameters which affect part quality and accuracy; producing simple test pieces, Standard test parts and End-User parts; and comparing the two systems to determine the range of parts suitable for each in terms of complexity and size.
Gains expected from these techniques are reductions in lead-time to manufacture prototypes (e.g. up to 95%) and reduced prototype manufacturing cost of 10% to 90%. Demonstration machines will be produced during this project capable of producing complicated metal components directly from 3D CAD data. These systems will have a wide range of use in a large number of industrial sectors and if applied across the European Mechanical industry there would be a market for machines of 750 Million ECUs over approximately 5 years. The immediate end-users of this technology are in the automotive component and the truck industry.
Funding SchemeCSC - Cost-sharing contracts
NG7 2RQ Nottingham
NG7 2RD Nottingham