Investigation of morphology characterization and mechanical properties of nano-flux (MnO) powder for tig welding

A lot of experiments have been carried out on varying welding parameters and its effects are studied. Not much work has been done on fluxes for TIG welding. This research work makes use of nano-flux (MnO) welding powder developed from agro waste (banana peel). TIG welding originally do not use flux powder, but in a bid to improve weld properties, flux was introduced. Mild, Galvanized and Stainless steel of plates and Rods were used as parent metals for the experiment. Eight (8) pieces each of Mild and Galvanized steel plates of 50 x 50 x 5mm, Mild and Stainless steel rods of 3.8 x 28mm length were prepared. The samples used were welded in three categories; iincludes without flux, with control (Imported) and nano-flux powder. These samples were subjected to hardness, impact, tensile, SEM and TEM examinations. Results of the hardness in the base metal, weld joint and heat affected zone for the galvanized and mild steel with nano-flux powder gave the best hardness of 206.21, 151.67, 110.56 and 111.95, 120.3, 182.99 BHN respectively. It was also observed that nano-flux welded samples gave maximum impact for mild and stainless steel as 2024.11 and 925.32, tensile stress of mild and stainless steel as 178.47 and 81.59 and tensile strain of mild and stainless steel as 0.0282 and 0.013. Micro-structural analysis results, with the use of SEM and TEM have revealed the micro-structural properties of the weld with the application of the nano-flux to have improved the structure, surface and pattern of the welds as compared to the imported flux and control weld. It also established that application of flux powder in TIG welding improved the welded joint hardness and the structure of the weld.