Showing 4 results for Amini
M. Sadeghi Gogheri, M. Shabani, E. Mirzapour, M. Kasiri, K. Amini,
Volume 2, Issue 1 (Journal OF Welding Science and Technology of Iran 2016)
Abstract
In this study, commercially pure titanium and aluminum alloy 5083 in connection rotational speed of 1120 rpm and a feed rate of 50 mm per minute for butt welding by friction stir welding has been successfully completed. Micro-structure, hardness and tensile test was conducted on the connection. Welding area is a composite of aluminum and titanium particles that the particles plays an important role in increasing hardness and tensile strength. Welding area is also has three areas. Vickers hardness is 480 times the area of welding means that the hardness in the area of the base metal of titanium and aluminum increased by 16% and 60% for titanium aluminum intermetallic compounds is created in the area is weld.
A. Lori Amini, H. Sabet, M. Ghanbari Haghighi ,
Volume 6, Issue 2 (Journal OF Welding Science and Technology 2020)
Abstract
In this investigation, the AISI 2205 duplex stainless steel was welded in the form of bead on plate by A-TIG process with different amount of the ZrO2 and TiO2 activated fluxes. The results of the visual inspection showed that the specimen with 50% ZrO2 and 50% TiO2 activated flux, had the lowest face width and the specimen with contains 90% ZrO2 activated flux, had the highest penetration depth. Also, the results showed that the angular distortion of the specimens with mix of the ZrO2 and TiO2 activated flux were 225% less than the specimen without activated flux. The results of macroscopic examination of different samples showed that the maximum length and width of the macroscopic grains were related to the sample with 90% ZrO2 activated flux and the smallest length and width of the macroscopic grains were related to the sample with 90% TiO2 activated flux. The hardness test results showed that the highest hardness of the samples was gained to 90% TiO2 activated flux specimen with 950 HV and the lowest hardness value for the sample with 90% ZrO2 activated flux with 410 HV. The results of all tests showed that surface activated fluxes (ZrO2 and TiO2) affected to the depth of penetration, face width, angular distortion, length and width of macroscopic grains and the hardness of weld metal by changing the longitudinal and transverse melt flow in the weld pool.
Hosseinn Soleimani, Kamran Amini, Farhad Gharavi,
Volume 7, Issue 2 (Journal OF Welding Science and Technology 2022)
Abstract
In this research, butt joining of Al2024 and Al7075 plates were performed by Friction Stir Welding (FSW) and the effect of tool position on microstructural and mechanical properties in about 1 mm from center line of joint towards the advancing side (AS) and the retreating side (RS) was investigated at three positions of +1, 0, -1 mm. In this regard, the plates of Al2024 and Al7075 were selected as the AS and the RS, respectively. In this joining method, transvers speed of 200 mm/min and tool rotation speed of 600 rpm were chosen. Macro- and Micro- structures of various welding areas and fractography of samples were evaluated by optical and scanning electron microscopies. In addition, mechanical properties were investigated using micro-hardness and tension tests. From the obtained macro-structures, it was observed that in all three joints, the surface of weld was without any defects (i.e., porosity, lack of penetration…). With varying tool offset position, welding micro-structure morphology was changed from homogeneous mode to layer or onion ring- shaped mode. Moreover, with varying tool position into the AS-side, tensile strength increased about 17.5% as opposed to the zero-tool position, but there was a decreasing about in tensile strength with changing tool position towards the RS-side as compared with the zero-tool position. Value of micro-hardness was approximately similar in all welded samples, but the highest value of hardness was observed at the weld zone (WZ). Thus, the obtained results showed that with varying tool position into the AS-side, mechanical properties were improved as opposed to the zero-tool position and tool position towards the RS-side.
M. Bozorgmehr, A. Heidari, K. Amini, M. Loh Mousavi, F. Gharavi,
Volume 9, Issue 2 (Journal OF Welding Science and Technology 2024)
Abstract
In the present study, friction stir process (FSP) was used to produce AL/ZrO2/ZrSiO4 surface hybrid composite at a fixed rotation speed of 1400 rpm and traverse speeds of 20, 25, 31.5 and 40 mm/min. Therefore, the purpose of the mentioned study is to investigate the effect of tool traverse speed on the microstructure, hardness and wear behavior of the above-mentioned surface hybrid composite and compare it with base material aluminum 5052. Investigations showed that as a result of FSP operation, a fine-grained structure is created, which improves the hardness and wear resistance of the samples compared to the base sample with the presence of ZrO2 and ZrSiO4 particles. Also, the results showed that among the FSP samples, the sample with a speed of 20 mm/min has the highest hardness and wear resistance. The reason for this is that in this sample, due to the lower traverse speed compared to other samples, more heat has been generated, which has led to more suitable particle distribution and more fine particles. Therefore, in the sample with the traverse speed of 20 mm/min, the hardness and wear resistance increases by 27.3% and 68.9% respectively compared to the base material sample. Also, the examination of the wear surfaces of the samples showed that the wear mechanism in the base sample is strong adhesive wear, and as a result of the FSP operation and surface compositing due to the fineness of the grains and the increase in hardness, the wear mechanism has become weak adhesive, so the wear resistance of the sample is FSPs have been improved.
