Integration of reverse engineering and rapid technologies for rapid investment casting of gas turbine blades

Abstract

The aim of this research work is to offer a unique procedure of integrated Reverse Engineering (RE) and Additive Manufacturing (AM) technologies through implementation of a comprehensive experimental study to present an extensive comparison between applicable rapid technologies for blade rapid investment casting. Different direct and indirect AM techniques were used to produce sacrificial investment casting patterns. In addition, an aluminium mould of a blade for wax injection was fabricated using Computer Numerical Control (CNC) machining to compare conventional investment casting with the proposed rapid investment casting process. Dimensional inspection of cast blades showed that the MultiJet Modelling (MJM) method has the most economic justification and compatibility with blade rapid investment casting and it can be considered as an alternative to conventional wax precision CNC machining. On the other hand, sacrificial patterns produced by the Perfactory system showed lower applicability for investment casting due to pattern flexibility and difficulties in burn-out step. As for examined rapid tooling technologies, silicone rubber moulding was not a stable technique for small batch fabrication of blade wax patterns. In contrast, the results proved that epoxy resin tooling could make possible new cost-effective approaches for low volume production of gas turbine blades.