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This research aimed to study the induction in-situ heated hybrid friction stir welding (IAFSW) method to join AA5052 aluminium alloy with X12Cr13 stainless steel (SS) to enhance joint strength. The potency of this method on the mechanical properties and microstructural characterizations were also investigated. The results show that the transverse tensile strength gained was 94% of the AA5052 base metal that is 229.5 MPa. This superior strength was achieved due to the annealing that happened to the AA 5052 region and elevated plastic flow in the weld zone by the in-situ induction heating, which resulted in the elongation of the weld region. The microstructure characterization indicates that a refined grain structure was gained in the nugget zone without defects.

Friction Stir Welding (FSW) was carried out to examine the influence of filler materials and varying process parameters on the microhardness and the joints corrosion resistance properties. Aluminium alloys 6082 and 5052, having 8 mm thickness was joined by varying parameters. The primary process parameters are rotational speed, tool travel speed, plunge depth, filler holes centre distance and filler ratio. The hardness at the weld nugget zone and corrosion rate evaluations were analyzed. The best results were obtained for the parameter combinations of 1150 rpm tool rotation, 130 mm min−1 tool travel, 0.2 mm tool plunge, the filler holes centre distance 2 mm and a powder filler made of 95% magnesium and 5% chromium.

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The coronavirus disease 2019 (COVID-19) rapidly spread to over 180 countries and abruptly disrupted production rates and supply chains worldwide. Since then, 3D printing, also recognized as additive manufacturing (AM) and known to be a novel technique that uses layer-by-layer deposition of material to produce intricate 3D geometry, has been engaged in reducing the distress caused by the outbreak. During the early stages of this pandemic, shortages of personal protective equipment (PPE), including facemasks, shields, respirators, and other medical gear, were significantly answered by remotely 3D printing them. Amidst the growing testing requirements, 3D printing emerged as a potential and fast solution as a manufacturing process to meet production needs due to its flexibility, reliability, and rapid response capabilities. In the recent past, some other medical applications that have gained prominence in the scientific community include 3D-printed ventilator splitters, device components, and patient-specific products. Regarding non-medical applications, researchers have successfully developed contact-free devices to address the sanitary crisis in public places. This work aims to systematically review the applications of 3D printing or AM techniques that have been involved in producing various critical products essential to limit this deadly pandemic’s progression.

Induction Heated Friction Stir Welding (IH-FSW) was conducted using two varying parameters and two fixed parameters. The microstructure evaluation shows that the nugget zone’s grain size is smaller while comparing with the parent metal. Due to dynamic recrystallization during the induction heated friction stir welding, well-equiaxed grains were found in the nugget zone. The microhardness test reveals that the welded region have improved hardness than the parent metal; the high hardness was attained in the heat-affected zone. The 3 h and 24 h of weight-loss corrosion test methods were conducted using the coefficient of 0.5 M H2SO4, showing that the stir zone’s corrosion resistance is better than the parent material. The given parameter combinations obtain the best results, tool rotation of 1250 rpm, welding speed of 45 mm min−1, shoulder penetration of 0.50 mm and induction heat input of 441.8 °C at 50 W.

The high entropy alloy (HEA) filler used during the fabrication method determines the reliability of HEAs for steel-aluminum dissimilar alloy configuration. HEAs have a direct impact on the formation of intermetallic compounds (IMC) formed by the interaction of iron (Fe) and aluminum (Al), and influence the size of the joint’s interaction zone. A novel welding process for Fe-Al alloy joints was developed to prevent the development of a brittle iron-aluminum interface. This research involved investigation of the possibility of using HEA powdered filler. Fe5Co20Ni20Mn35Cu20 HEAs was used as a filler for the laser joining lap configuration joining hyper-duplex stainless steel UNS S33207 to aluminum alloy 6061. This HEA has unique properties, such as high strength, good ductility, and high resistance to corrosion and wear. A tiny portion of the stainless-steel area was melted by varying the welding parameters. The high-entropy alloy (HEA) with slow kinetic diffusion and large entropy was employed to aid in producing solid solution structures, impeding the blending of iron and aluminum particles and hindering the development of Fe-Al IMCs. The weld seam was created without the use of Fe-Al IMCs,. The specimen broke at the HEAs/Al alloy interface with a tensile-shear strength of 237 MPa. The tensile-shear strength achieved was 12.86% higher than for the base metal AA 6061 and 75.57% lower than for the UNS S33207 hyper-duplex stainless steel.