Research Projects

Internal or cross-connected internal geometries with stringent surface quality have wide engineering applications. In Additive Manufacturing (AM), components are developed layer-by-layer, reducing the need for expensive tools or complex types of equipment for producing very complex internal features. Metallic alloy-based additive manufacturing processes such as Direct Energy Deposition (DED) and Powder Bed Fusion (PBF) have proven their viability in producing complex metallic components for high-strength and difficult-to-machine metallic alloys such as Inconel 718 superalloy. In additive manufacturing, poor surface integrity is the major challenge. Therefore, finishing and superfinishing of additively manufactured components is in the research spotlight to make the additively manufactured components market ready. To enhance the surface quality, various post-processing techniques such as machining (milling, turning), laser polishing, shape adaptive grinding, chemo-mechanical finishing, chemical finishing and abrasive flow finishing have been proposed by various researchers. Specifically, finishing the internal surface of the complex features, such as curved holes, is the major challenge owing to the non-reachability of the conventional tools. Recently, abrasives or chemical finishing methods have been proposed by a few researchers for the internal surfaces of the holes. However, the surface finish obtained by chemical finishing is highly localized to certain regions, like grain boundaries, and abrasive finishing is limited to straight holes only. At the curve internal surface, centrifugal force causes abrasives to hit mostly the concave wall. So, even though additive manufacturing enables us to create difficult geometry, especially complex internal features, the homogeneous finishing of these internal features is still very challenging. Through proper setup design and analysis, the abrasive-based finishing process can be modified to overcome challenges in improving the surface quality of the complex internal features of components made by additive manufacturing. This proposal proposes a novel method by introducing an oscillatory non-uniform magnetic field assisted abrasive flow finishing for homogeneous finishing of the internal surfaces of curved holes of complex features by designing and developing an indigenous finishing set-up. The oscillatory non-uniform magnetic field will encounter the effect of centrifugal force, enabling the flow path to be curved, aligning with the bend of the internal feature. Setup design will follow design thinking approach. Both designing and fabrication will be in-house. Design analysis and optimization will be done by computer simulations. Later experiments will be carried out and the results will be used to test and enhance the overall performance of the setup. The second part of the project is to prepare chemically modified magnetorhelogical solution with suspended abrasive for enhancing the finishing speed. Once the appropriate material for the chemical slurry is prepared, then analysis of the effect of process parameters such as abrasive powder type, abrasive size, abrasive density, chemical concentration, magnetic field on super finishing performances will be carried out. Further, to understand the mechanism of nano-cutting and its effect on surface and subsurface defects, a multiphysics simulation will be carried out through the finite element method, Computational Fluid Dynamics, and a molecular dynamics simulation approach. Upon successful completion, the project will deliver a novel, low-cost Indigenous method and machine setup for precision finishing of curved internal surfaces in additively manufactured components. This innovation offers a competitive edge for national defence, space, and biomedical sectors, with strong potential for patenting and commercialization through technology transfer.