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Joining of the similar & dissimilar materials alloys using heat of the friction in currently being used, especially for non-ferrous alloys which are considered as non-weldable alloys. Al 2024-T6 & Al 6061-T6 having length of 70mm and 12mm diameter were welded by using the friction welding process. Similar and dissimilar welded samples were obtained by applying different combinations of welding parameters like friction pressure 30bar, forging pressure from 50 to 60 bar, and rotational speed of 2200 rpm. Vickers microhardness and Tensile test was performed on similar and dissimilar welded samples. Test shows that ultimate tensile strength and hardness of the similar welded joint was greater than their respective base metals welds. Dissimilar weld samples have hardness and ultimate tensile strength greater than the base Al 6061-T6, and less than the base Al 2024-T6. From results, it was clearly shown that as forging pressure increased from 50 to 60 bar, ultimate tensile strength and hardness of the similar and dissimilar welded samples increased. Joints were analysed to investigate the fractography of all welded samples. All welded samples fractured on the base metal alloy and show the formation of the cup and cone like structure which indicate the ductile fracture of the joints.

Strengthening of metals as a function of metal working and thermal treatment is being utilized effectively in steel structures. Effect on strength beyond thermomechanical treatment has been the focus of this research by imprinting a nature inspired pattern on one side of the sheet metal. Pangolin scale pattern overlapped on AISI 1040 sheet metal while preserving its base treatment. Microstructure, impact toughness, hardness, and tensile strength with notch opposite to worked side was investigated after forging and post forging heat-treatment. After heating at 800°C, overlapping patterned forging was done on one side of two plates and then subsequently cooled in two ways, air cooled, and water quenched. To analyze the effect of forging and heat treatment, Charpy impact, UTS, hardness tests, and metallography were carried out on the heat treated (forged + quenched), untreated (forged + air cooled) and base (as received) specimens. The Room temperature Charpy test showed that the untreated specimen has the highest impact toughness of 120 J as that of the base and heat-treated specimen, 44 J and 60 J respectively. The heat-treated specimen showed an increase in macro and micro hardness than for the base and untreated specimens. Whereas the UTS has dropped in untreated and heat-treated specimens as compared to the base specimen, because in tensile test load is applied uniformly throughout the specimen so the stress concentrations in the unforged side of the metal higher than the side which is forged with overlapping patterns.