scholarly journals Microstructure and Mechanical Properties of Friction Stir Welded Joints Between Commercially Pure Copper and Al 6351 Alloy

2017 ◽  
Vol 62 (3) ◽  
pp. 1819-1825
Author(s):  
V.C. Sinha ◽  
S. Kundu ◽  
S. Chatterjee

AbstractIn the present study, the effect of tool rotational speed on microstructure and mechanical properties of friction stir welded joints between commercially pure copper and 6351 Al alloy was carried out in the range of tool rotational speeds of 300-900 rpm in steps of 150 rpm at 30 mm/minutes travel speed. Up to 450 rpm, the interface of the joints is free from intermetallics and Al4Cu9intermetallic has been observed at the stir zone. However, Al4Cu9intermetallic was observed both at the interface and the stir zone at 600 rpm. At 750 and 900 rpm tool rotational speed, the layers of AlCu, Al2Cu3and Al4Cu9intermetallics were observed at the interface and only Al4Cu9intermetallics has been observed in the stir zone. The maximum ultimate tensile strength of ~207 MPa and yield strength of ~168 MPa along with ~6.2% elongation at fracture of the joint have been obtained when processed at 450 rpm tool rotational speed.

2020 ◽  
Vol 62 (8) ◽  
pp. 793-802
Author(s):  
Şefika Kasman ◽  
Sertan Ozan

Abstract In the present study, AA 2024-T351 plates with a thickness of 6 mm were joined using the friction stir welding technique with three different tool rotational speeds and two different pin profiles. Microstructural features and mechanical properties of welded joints were investigated. The grains in recrystallized regions along the stir zone were observed to be almost with invariable sizes. The grain size was revealed to increase with the increase in tool rotational speed. The average grain size was observed to dramatically increase from 2.3 μm to 5.6 μm for welded joints produced with pentagonal shaped pin. All the welded joints were observed to contain defects; the presence of defects exhibited a negative effect on the tensile properties of the welded joint. Most of the defects were observed to localize at the root region of joints. The joint, welded with the tool rotational speed of 250 rpm using pentagonal shaped pin, exhibited ultimate tensile strength with a value of 365 MPa. The ultimate tensile strength of welded joints was found to be higher with the decrease in the tool rotational speed. The welding efficiency of joints was compared with the ultimate tensile strength of base metal; notably, welding efficiency values between 46 % and 80 % were achieved. Microstructural characterizations revealed that Al2Cu (θ phase), Al2CuMg (S phase), and AlCuFeMnSi, Al7Cu2Fe intermetallic particles were dispersed in the stir zone.


2019 ◽  
Vol 969 ◽  
pp. 720-726
Author(s):  
Ajay Kumar Revelly ◽  
B. Rajkumar ◽  
V. Swapna

The main aim of the present topic is friction stir welding (FSW) of Aluminium HE-30, which shows that improved microstructures, strong weld and with less of defects. In the other hand, an attempt was made to correlate the welding parameters and mechanical properties. In the present investigation four rotational speeds of 1000 rpm, 1200 rpm, 1400 rpm and 1600 rpm with travelling speed of 30 mm/min. and tool geometry (straight cylindrical) was chosen. It was observed that the tool rotational speed is a sensitive parameter to decide the ultimate tensile strength and yield strength of the present material. Similarly, the hardness of Al plates is improved at the weld zone. Hence, it is suggested that to consider a parameter such as welding tool rotational speed, travelling speed and materials in selecting the welding methods of sound joints, because it influences the microstructure and mechanical properties in various applications. In the present study, non-destructive tests are also confirmed the defective nature of the weld zone of Al plates.


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