Research Projects

Additive manufacturing (AM) is referred as the most successive pillar of Industry 4.0. Metal AM primarily involves fusion and solid-state techniques. In fusion-based AM (laser, electron beam melting, laser-engineered net shaping, selective laser melting and wire arc additive manufacturing-WAAM), the material is brought into a molten state and then solidified in a layering fashion to develop the required geometry. Since the material was brought into a molten state, so issues like porosity, shrinkage, undesirable intermetallic compounds, cracking, residual stress, lack of fusion (in laser and electron beam melting technique) and anisotropy have proven their existence in the final developed structure. Spatter and fumes evolved under the selection of WAAM approach. To overcome such limitations, solid-state AM techniques (friction welding-based AM-FWAM and ultrasonic welding-based AM-USWAM) are imposed. FWAM approach is an evolving solid-state AM that uses frictionally developed heat to impart severe plastic deformation to the filler material, so the deposited material never brings into the fusion state. It has beneficiary over fusion-based AM techniques in terms of restriction of solidification defects like porosity, cracking, shrinkage, unavailability of undesirable intermetallic compounds, energy efficiency, and eco-friendliness due to lack of fumes and spatter. Moreover, it does not require any inter-layering time as the material is never brought into the molten state, which results in a refined grain structure that boosts the structural and mechanical performances. It also imparts accuracy and offers high part-building rates than powder bed fusion and direct energy deposition techniques. FWAM includes techniques like friction stir AM (FSAM) using flat plates, friction surfacing (FS) using limited length cylindrical rods, and additive friction stir deposition (AFSD). In these processes, it is essential to refill a new consumable material to the tool holder due to limited raw material length. Looking into such length limitations, a wire-based FSAM technique (W-FSAM) can be explored where a filler wire is fed continuously through the tool. The filler wire gets compacted and thermoplasticized under the action of friction between tool and substrate and later on with the deposited layers. W-FSAM imparts uninterrupted deposition that could enhance the building rate, transfer efficiency, microstructural refinement, and strength. Magnesium alloy has abundant applications in aerospace, automobile, electronic, and biomedical (temporary implant) sectors owing to low density, high specific strength, good biocompatibility, and biodegradability. Moreover, it has been treated as a 3rd generation biomaterial due to the availability of regeneration and support of functional bone tissues. Looking into the beneficiaries of magnesium alloy in several sectors, the W-FSAM techniques can be explored, where Mg feedstock is supplied in wire form.