Showing 4 results for Rotational Speed
I. Khodai Delouei, H. Sabet , V. Abouei Mehrizi,
Volume 4, Issue 2 (1-2019)
Abstract
Friction Stir Welding is one of the solid-state processes and today it has been used to join different types of materials. Friction stir welding does not have many problems and limitations due to melting and solidification of weld metal and by controlling its variables, the microstructure and desired mechanical properties can be achieved at the joint. Recently, in most industrial areas, due to its lightness and energy saving, much attention has been paid to the joining of aluminum alloys. The present study investigates the microstructure and evaluation of mechanical properties of friction stir welding in AA2024 and AA6061butt welds. A cylindrical threaded tool was used to join 5 mm thick plates at rotational speeds of 800, 1000 and 1200 rpm and traverse speeds of 30, 50, 70, 90 and 110 mm / min. In order to perform the necessary investigations, metallurgical observations were performed by optical microscope and scanning electron microscope equipped with a chemical analysis system of the elements, as well as mechanical tests of tensile strength and micro hardness. The results showed that the difference between the two alloys causes hardness variations in the nugget zone and a large hardness drop at the transition between the zone composed of both alloys and the 6061 zone. By increasing the traverse speed from 30 to 110 mm / min at constant rotational speeds of 800, 1000 and 1200 rpm, due to reduced input heat, the grain size decreases and the hardness and strength increase. Also, the highest tensile strengths and hardness were 221.6 Mpa and 111.05 Vickers, respectively, for a sample welded at a rotational speed of 1000 rpm and a traverse speed of 110 mm / min.
Ramin Delir Nazarlou, Dr Faraz Omidbakhsh, Dr Javad Mollaei Milani,
Volume 6, Issue 1 (8-2020)
Abstract
Friction stir welding (FSW) is an economic and high quality technique at aluminum welding and joining methods. The most important factor in the soundness of this type of welding, is the mechanism of material transfer in each tool rotation. The materials transfer during the welding process involves horizontal and vertical movement that caused by extrusion process and forging force (the tilt angle due to forging force and on the other hand, shape of pin due to the extrusion process). One of the most important parameters in FSW process is the effect of rotational speed in the welded zone. In this study, the effect of rotational speed at constant welding speed, in the butt joint of pure commercial aluminum, was investigated. The results of the study showed that, increasing the rotational speed due to increases the amount of material transfer in the weld zone. The welded zone was investigated by appearance weld zone experiments and using radiography tests. Also weld zone was investigated in macro and microstructure by using cross section. Then the micro hardness testing has been used by cross section at welded zone. In order to investigate the mechanism of materials transfer during the process, the electrical resistivity test has been used to analyses the amount of materials transfer in the weld zone. Results shows that, increasing rotational speed due to increasing the amount of materials transfer in the weld zone and decreasing the amount of defects in the weld zone.
N. Ebrahimi, F. Omidbakhsh,
Volume 7, Issue 1 (8-2021)
Abstract
In this paper, the effects of welding parameters involving tool shape, title angle, rotational speed and welding speed on the S-shape defect formation have been investigated. For this purpose friction stir welding process were done on the Al-1085 plates by cylindrical, Triangle and square pins. The welded sections were studied by metallographic, radiography and SEM methods. The results showed that the S-shape defect was formed in the 1120 rpm, 1º title angle, 160mm/min welding condition. It is believed that the higher heat input in this welding condition with low welding speed would lead to more oxidation of Aluminum and so oxide particles formation. These oxide particles precipitate in a S shape pattern during the materials transfer between Advancing Side and Retreating Side sites which leads to S-shape defect formation.
P. Chamani, H. Sabet, M. Ghanbari Haghighi,
Volume 9, Issue 2 (1-2024)
Abstract
In this study the effect of rotational speed and tool angle parameters on the microstructure and mechanical properties of the AZ91/CP-Ti joint was investigated, for this reason the sheets with 4 x 26 x 100 mm dimensions were prepared and joint by FSW with different rotational speed (800, 1200 and 2500 rpm) and the tool angle (0.5, 1 and 3 degrees). After joining, the samples were cut and prepared for study of microstructural and mechanical properties. OM and SEM examination shows that the structure of AZ91/CP-Ti nugget zone includes alpha grains and the microstructure of the mix zone on the AZ91 side includes α-magnesium coaxial grains with Mg17Al12 intermetallic compounds. The results of the tensile test show that the maximum tensile strength value (160 MPa) related to the rotation speed of 2500 rpm and the tool angle of 1 degree. It was also determined that the rotation speed of 800 rpm was not suitable for joining of AZ91/CP-Ti. On the other hand, it was observed that by increasing the tool angle the work piece, initially leads to an increases the strength from 141 MPa to 160 MPa and then decreases to 132 MPa. the results of the Vickers hardness test show that the average of the nugget zone hardness was to 173, which is higher than the hardness of AZ91 alloy (61 Vickers) and near to the hardness of CP-Ti (167 Vickers).
