Research Projects

High pressure Compressor (HPC) blades, typically made from hard-to-machine superalloys like Inconel 718 and titanium alloys, are essential for efficient energy conversion in aircraft engines. While traditional CNC machining has limitations, such as tool wear, high cutting forces, and potential deformation of thin-walled structures, electrochemical machining (ECM) offers significant advantages. ECM allows for precise, stress-free machining of complex geometries without inducing thermal or mechanical stress, which is crucial for thin aerofoil sections in HPC blades. Despite these advantages, ECM technology requires further refinement, particularly in cathode tool design, electrolyte flow control, and optimization of process parameters to improve machining accuracy and surface quality. Indian electrochemical machine tool manufacturers Sinergy nanosystems and Interface Design Associates specialise in micromachining applications, whereas machine by Metatech industries do not have capacity to fabricate complex geometries with free from surfaces. As far as PIs know, no research group addresses electrochemical machining compressor blade concerns in country. This justifies developing an ECM configuration for turbojet engine component research. The scientific objectives of this research are to design cathode tools for blade machining using a multiphysics simulation model for designing the tools and blade machining; to develop a CNC-controlled twin-feed cathode based experimental ECM setup; to optimize ECM input parameters via data-driven modelling and fabricate machine Inconel 718 HPC blades with a uniform surface finish of approximately Ra ≈ 200 nm; and to conduct detailed characterization of blade surfaces, assessing surface roughness, topology, micro-cracks, and residual stresses. The current approach of the proposed research is to mimic and scale down a general purpose ECM machine tool made by one of the German companies i.e., PEMTEC (cost = 15 Cr INR) (on which I had hands-on experience during my SERB SIRE fellowship visit). The machine tool will be equipped with twin-feed negative aerofoil shaped cathode (designed by numerical modelling and machined using 5-axis milling machine) to precisely machine a cuboidal workpiece of Inconel718 to a HPC blade. The parameters of higher machining and finishing rates will be optimized and blades with ≈ 200 nm Ra will be produced. The successful completion of the project will be a helpful step for Indian turbojet engine manufacturers to make critical turbojet engine components such as turbine & compressor blades, turbine casing, bypass duct and engine blisk. Scientifically designed tool and extensive experimental research would lead to fabrication of high quality HPC blades which will tested at gas turbine research establishment (GTRE). If the blades qualify the quality check, the production-scale machine will be developed in collaboration with GTRE (LOI attached) and industries.