Design and Fabrication of the Micro Turbine for Micro Gas Turbine Engine

Abstract

The designing of a micro turbine for micro gas turbine engine is presented in this paper. Micro power system is becoming more and more important for micro- and nano-scale system. The fast development of MEMS (Micro Electromechanical Systems) has strongly enhanced the application of new harder work materials. The fabrication of metallic 3D microstructures has been one of the most attractive topics of micro machining. Currently the basic materials of Micro-turbine Engineering were nonmetal materials such as SiC, most of them are 2D or quasi-3D structures. As a low cost, flexible, good repeatable machining process with negligible process forces, micro-EDM milling is well suited for freeform metallic micro structures. A three-dimensional micro turbine was fabricated by micro-EDM milling. A major problem in micro-EDM milling of complex 3D structure by using micro-electrode is the electrode wear. For reducing the impact of electrode wear, A new CAM system based on the UG software platform is developed in order to get good accuracy 2and higher efficiency. A simple tool path generation by CAD/CAM software and a general electrode wear compensation strategy is presented. The wear compensation can be apart from the design of CAD/CAM systems, so existing common CAD/CAM systems can be used to generate milling tool path with an unequal thickness lamination. And then post process for wear compensation and EDM milling can be done to modify tool path by adding wear compensation. The micro turbine blades of which the material is nickel alloy (GH4169) were successfully fabricated by using this strategy. The diameters of turbine are 2.8mm, and the height of each blade is 0.4mm.