Dr M. Safari, Dr H. Mostaan,
Volume 1, Issue 1 (1-2016)
Abstract
Weldability of high carbon steels due to the high percentage of carbon and consequently formation of martensitic structure is very poor. In this research, resistance spot welding of eutectoid high carbon steel 1075 is experimentally and numerically investigated from various points of view. The effect of welding current as one of the most effective parameters on failure mode, mechanical properties and nugget size diameter in resistance spot welding is analyzed with experimental tests and numerical simulations. The results show that with increase of welding current, the diameter of nugget size is increased and consequently the failure mode changes from interfacial mode to pull out mode.
Mr. Ramin Dadashpour, Dr. Moosa Sajed, Dr. Mohammad Ali Saeimi Sadigh, Dr. Arezou Abyazi, Dr. Akbar Heidarzadeh,
Volume 9, Issue 2 (8-2025)
Abstract
In this study, the Friction Stir Welding process was employed to repair artificial cracks and grooves in 7075 aluminum alloy. Samples with different groove depths (0.5, 1, 1.5, and 2 mm) were prepared and evaluated through experimental tests, metallographic analysis, tensile testing, and numerical simulation using Abaqus software. The results showed that the Friction Stir Welding successfully repaired the defects without creating voids or surface irregularities. Microstructural observations in the stir zone revealed that dynamic recrystallization led to the formation of fine and homogeneous grains, resulting in improved hardness and tensile strength. The specimen with a 1 mm groove depth exhibited the best mechanical performance, with a maximum hardness of approximately 109 HV and the highest tensile strength among all samples. Conversely, samples with 0.5 and 2 mm groove depths showed void formation and reduced strength due to insufficient or excessive heat input and uneven material flow. Both experimental and simulation results confirmed that a groove depth of 1 mm provides optimal conditions for defect repair in 7075 aluminum alloy.
