Dissimilar friction-stir welding of 430 stainless steel and 6061 aluminum alloy: Microstructure and mechanical properties of the joints

Author(s):  
Sirvan Zandsalimi ◽  
Akbar Heidarzadeh ◽  
Tohid Saeid

The effect of friction-stir welding parameters on the microstructure and the mechanical properties of the dissimilar 430 stainless steel and 6061 aluminum alloy joints were investigated. Optical and scanning electron microscopes in conjunction with energy dispersive X-ray analysis were employed to study the microstructure of the joints. Tensile and microhardness tests were used to evaluate the mechanical properties. The results showed that the best appearance quality was achieved at a rotational speed of 900 r/min, a traverse speed of 120 mm/min, and a tool offset of zero. The tool offset was the most effective parameter affecting the weld quality. The stir zone of the joints had a composite structure in which the dispatched steel particles were distributed in aluminum. The best interface quality belonged to the joints welded at an offset of zero, which had a serrated nature with mechanical locking of the dissimilar parts. However, at negative and positive values of offsets, formation of voids and microcracks reduced the tensile properties of the joints. The tensile fracture of the joints occurred in the heat affected zone of the aluminum part, which had the lowest hardness amount between the microstructural zones. The fracture surfaces of the tensile specimens showed bimodal behavior.

2020 ◽  
Vol 25 ◽  
pp. 563-569 ◽  
Author(s):  
Saket Choudhary ◽  
Sahaj Choudhary ◽  
Siddharth Vaish ◽  
Avani Kumar Upadhyay ◽  
Amneesh Singla ◽  
...  

2018 ◽  
Vol 8 (1) ◽  
pp. 2493-2498 ◽  
Author(s):  
A. W. El-Morsy ◽  
M. Ghanem ◽  
H. Bahaitham

In this work, the effects of rotational and traverse speeds on the 1.5 mm butt joint performance of friction stir welded 2024-T4 aluminum alloy sheets have been investigated. Five rotational speeds ranging from 560 to 1800 rpm and five traverse speeds ranging from 11 to 45 mm/min have been employed. The characterization of microstructure and the mechanical properties (tensile, microhardness, and bending) of the welded sheets have been studied. The results reveal that by varying the welding parameters, almost sound joints and high performance welded joints can be successfully produced at the rotational speeds of 900 rpm and 700 rpm and the traverse speed of 35 mm/min. The maximum welding performance of joints is found to be 86.3% with 900 rpm rotational speed and 35 mm/min traverse speed. The microhardness values along the cross-section of the joints show a dramatic drop in the stir zone where the lowest value reached is about 63% of the base metal due to the softening of the welded zone caused by the heat input during joining.


2018 ◽  
Vol 775 ◽  
pp. 466-472 ◽  
Author(s):  
K. Tejonadha Babu ◽  
S. Muthukumaran ◽  
C. Bharat Kumar

Friction stir welding (FSW), a new joining process is finding extensive use in the welding of aluminum alloy sheets. The metal transfer modes in the FSW cause the quality of the weld and its properties. The first mode of metal transfer is accomplished by the tool and shoulder, while the second mode occurs around the pin. In the present study, two different welding conditions, which were friction stir welding in the air (CFSW) and underwater friction stir welding (UWFSW) carried out at various welding parameters to weld the AA5052-O aluminum alloy sheets and determine the consequence of the first mode on the tensile strength of welded joints. Considerable grain refinement and enhanced mechanical properties were obtained in UWFSW joints. It Is observed that the first mode affect the tensile strength of the joint, also found that a linear correlation between the first mode and the tensile strength.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
J. C. Verduzco Juárez ◽  
G. M. Dominguez Almaraz ◽  
R. García Hernández ◽  
J. J. Villalón López

This work deals with the effect of a new “bolt-head” pin profile on the friction stir welding performance of the aluminum alloy 6061-T6, compared to traditional pin profiles. Friction stir welding parameters such as the tool rotation speed and the welding speed were investigated together with the different pin profiles; the results show that the new “bolt-head” pin profile leads to better mechanical properties of welded specimens. The pin profiles used in this work were the straight square (SS), straight hexagon (SH), taper cylindrical (TC), and the straight hexagon “bolt-head” (SHBH). It was found that the last pin profile improves the material flow behavior and the uniform distribution of plastic deformation and reduces the formation of macroscopic defects on the welded zone. Mechanical tensile tests on welded specimens were performed to determine the tensile strength: the specimens welded with the SHBH pin profile have shown the highest mechanical properties. An approach is presented for material flow on this aluminum alloy using the SHBH pin profile, which is related to the improvement on the resulting mechanical properties.


2017 ◽  
Vol 7 (3) ◽  
pp. 1619-1622
Author(s):  
J. A. Al-jarrah ◽  
A. Ibrahim ◽  
S. Sawlaha

This paper investigates the effect of axial force on the surface appearance and mechanical properties of 6061 aluminum alloy welded joints prepared by friction stir welding. The applied pressure varies from 1.44 to 10.07 MPa. The applied pressure was calculated from the axial force which exerted by a spring loaded cell designed for this purpose. Defect free joints obtained at an applied pressure of 3.62 MPa. The mechanical properties of the welded joints were evaluated through microhardness and tensile tests at room temperature. From this investigation, it was found that the joint produced with an applied pressure of 5.76 MPa exhibits superior tensile strength compared to other welded joints. The fracture of this joint happened at the base material.


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