Precision manufacturing of key components for an ultra miniature gas turbine unit for power generation

Abstract

Advanced and precise manufacturing is presented for two key components: a compressor and a turbine impeller (Ø 20 mm) for an ultra miniature gas turbine system as fuel-based power generation system. The total system fits in a cylinder with a diameter of 110 mm and a length of 120 mm. At this scale, major components such as turbine and compressor are subjected to challenging requirements such as high rotational speed (500,000 rpm), high turbine inlet temperature (1,200 K) and efficiency. The choices of material and manufacturing technique are critical. The components must endure the operational requirements and should be fabricated in high accuracy. In order to withstand the high centrifugal stress, a high-strength titanium alloy is used for the compressor. Using micro-milling, a three-dimensional complex and accurate structure is obtained. The turbine is made of a Si 3 N 4 -TiN ceramic composite to sustain the combination of elevated stress and temperature. A scrupulously developed process chain combines electrical discharge machining and grinding as manufacturing processes, which not only just preserve the surface integrity and the related material strength but also provide an adequate dimensional and geometrical accuracy.

Pneumatic and hydraulic microactuators: a review

“…Finally, we want to emphasize that the above overview on fluidic actuators is not exhaustive. In this review, we will for instance not discuss methods for droplet actuation [148,149] nor microrockets [150] and microturbines [151,152].…”

Numerical simulation and tool parameters optimization of aluminum alloy transmission intermediate shell

“…Dombovari 13 studied the milling simulation system for thin-walled parts, through data collection, analysis and noise reduction processing of the cutting process, realizing the stability and feasibility prediction of milling and turning machining methods for thin-walled parts of the magazine by developing a complete milling simulation optimization system. Liu 14 studied thin-walled titanium alloy compressor blades, he used the micro-milling machine tool Kern MMP and UG/CAM post-processing CNC programming to plan the tool path for the finishing process of the tiny impeller blades. Finally, he used a 1 mm diameter Carbide ball end milling cutter enables high-precision machining of the entire blade.…”

“…Marques 16 studied high-temperature alloy ship engine shells, innovatively used ceramic tools (Al2O3 + Si CW) for cutting high-temperature alloys, observed the flank wear of ceramic tools, analyzed the wear mechanism, and determined the optimal method for processing high-temperature alloy shells. In conclusion, according to the references [9][10][11][12][13][14][15][16] , numerous researchers have created mathematical models of cutting force or cutting temperature, and optimization algorithms to perform high-precision and high-quality machining of shells with complex profiles and difficult-to-machine materials. However, As the teeth of the manufacturing industry, metal cutting tools determine the surface accuracy and production cycle of the workpiece to be processed 17 , and the side milling method of integral end mills is widely used in the finishing process of thin-walled parts shells.…”

Research on Five-Axis Numerical Control Programming and Machining Technology of Micro Integral Impeller

“…The stainless steel micro-turbine rotor is machined by electric spark machining technology in the University of Ruin, Belgium [4]. In addition, the university also machined the titanium alloy micro-impeller by the Cohen micro-milling machine [5]. Imperial College of Technology uses an innovative method of excimer laser processing of axially structured microturbine transducers on PMMA materials [6].…”