M. Ansaripour, A. Soltanpoor, A. Ghasemi, M.r. Dehnavi,
Volume 2, Issue 1 (8-2016)
Abstract
The aim of this study was to evaluate the mechanical properties and corrosion behavior of friction stir welding (FSW) connection of A517 (B) steel plate. Mechanical properties and corrosion behavior of weld zone were evaluated after reaching to optimum FSW microstructure with the lowest martensite phase. Thus, after the identifying phase microstructure by SEM and XRD analysis, mechanical properties were analyzed by micro-hardness and tensile test. Micro hardness data shows slight increases in stir zone (SZ) compared with the base metal (BM); although a reduction of about 17% in hardness of heat-affected zone (HAZ) was sensible. Reduction of hardness in the HAZ was appeared as drop by about 12 percent of the yield strength and 19 percent of ultimate strength compared with BM. SEM images from fracture surface of the tensile sample showed bi-modal distribution of large and small Dimples being sings of softness of HAZ .Comparing corrosion behavior in solution consist of 3.5 wt% of NaCl showed that there was no passive layers to prevent dissolution of the metal in the SZ and BM. while BM and SZ had fairly similar corrosion rates, Difference of 50 mV between corrosion potential of SZ and BM showed that in galvanic condition, corrosion resistance of BM could be lower than SZ.
Dr. Hamidreza Rezaei Ashtiani, ,
Volume 9, Issue 2 (8-2026)
Abstract
The joining of dissimilar aluminum sheets is an important issue in the optimization of industrial joints due to the differences in physical, mechanical and metallurgical properties. In this study, the mechanical behavior and microstructural changes of bimetallic joints made of AA5052 and AA3105 alloys joined by two methods of TIG welding (TIG) and friction stir welding (FSW) were investigated and compared. First, preliminary experiments were carried out to optimize the parameters of the friction stir welding and TIG welding processes and to select appropriate levels of the process parameters. The results of mechanical experiments showed that in the FSW welded samples, the failure occurred mainly in the weld zone, but in the TIG welded samples, the failure occurred in the base metal. The tensile test results showed that the AA5052 sample had the highest tensile strength (273 MPa) and the highest elongation percentage (20%), and the F 3-5 welded sample with a strength of 89 MPa and 6% elongation performed worse than the T 3-5 welded sample and fractured in the weld area. The microhardness test results showed that the TIG welded sample had a higher hardness in the weld area than the FSW method due to the use of 5356 ER filler. Finally, by analyzing and comparing the results obtained from the tests related to the mechanical properties obtained from each method, it was found that the TIG method performed better than FSW in joining some alloys.
