Friction stir welding was performed on AA2024- T6 aluminum plates using different rotation and traverse speeds with the objective of improving the mechanical strength and microstructure properties. The influence of the traverse and rotation speed on the microstructures, mechanical properties and residual stresses of the welded Aluminum plates were investigated. By increasing the rotation speed, stirred zone grain size became larger. Besides, the homogenous second phase distribution was obtained. Furthermore, by increasing both rotational and traverse speeds, hardness of the thermo-mechanically affected zone and the stirred zone increase to base metal hardness. These welded plates that were fractured at advancing side have a maximum tensile strength equal to 71% of base plate strength which was obtained at 31.5 mm/min traverse speeds and 1120 rpm rotational speed. The longitudinal residual stress was diminished with decreasing of rotational speed by 1120 rpm at a constant traverse speed. In this conditions and by increasing the traverse speed by 31.5 mm/min, the maximum tensile strength was obtained as many as 48%. It was attributed to more plastic deformation and minimum grain size in the weld zone due to higher traverse speed. تفاصيل المقالة

In this study, effects of process parameters of Friction Stir Spot Welding were investigated on Al2024T3 which has poor weldability. Several spot welds were performed by the FSSW process on the 2mm aluminium sheets. The effects of main process parameters such as tool Rotational Speed (RS), Normal Plunge Depth (NPD), and Dwell Time (DT) on the joint strength were investigated. By increasing the tool rotational speed, the joint strength increased, consequently. The mean failure load improved 52% when the tool rotational speed increased from 800 rpm to 1120 rpm, whereas increasing the rotational speed from 1120 to 1600 did not have significant effect on the failure load. The results showed, increasing the normal plunge depth from 1.5 to 1.75 millimetre led to an increase in the failure load of spot welds by about 1.62 times. Also, the 3 seconds dwell time showed higher failure load compared to 2 and 5 seconds dwell time. تفاصيل المقالة

The widespread application of thermoplastic polymers in different aspects of industries hasmotivated researchers and companies to improve and upgrade their forming, joining and assemblingprocesses to overcome their limitations. One of the newest joining methods of thermoplastics isfriction stir welding which is based on frictional heat generated through contact between a rotatingtool and the workpiece. A hybrid thermal assisted friction stir welding approach was proposed inthis study for two Poly methyl methacrylate sheets. In this method, the stationary shoe was heatedup to the specified temperature and then the FSW tool was gradually plunged toward the clampedsheets. The effects of different process parameters such as rotational and traverse speeds and theheater temperature on the mechanical properties of the joints were studied. Results showed thatapplying the optimum rotational speeds of 1600 rpm and highest traverse speeds of 12.5 mm/minwith the stationary shoe heats up to 70% of base polymer melting temperature which leads to thehighest joint performance with strength equal to 95% of PMMA strength. تفاصيل المقالة