State-of-The-Art and Applications of 3D Imaging Sensors in Industry, Cultural Heritage, Medicine, and Criminal Investigation

3D imaging sensors for the acquisition of three dimensional (3D) shapes have created, in recent years, a considerable degree of interest for a number of applications. The miniaturization and integration of the optical and electronic components used to build them have played a crucial role in the achievement of compactness, robustness and flexibility of the sensors. Today, several 3D sensors are available on the market, even in combination with other sensors in a “sensor fusion” approach. An importance equal to that of physical miniaturization has the portability of the measurements, via suitable interfaces, into software environments designed for their elaboration, e.g., CAD-CAM systems, virtual renders, and rapid prototyping tools. In this paper, following an overview of the state-of-art of 3D imaging sensors, a number of significant examples of their use are presented, with particular reference to industry, heritage, medicine, and criminal investigation applications

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

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