scholarly journals Effect of Tool Offset on the Microstructure and Properties of AA6061/AZ31B Friction Stir Welding Joints

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 546 ◽  
Author(s):  
Huachen Liu ◽  
Yikun Chen ◽  
Zhenhua Yao ◽  
Feixiang Luo

Friction stir welding was carried out on AA6061/AZ31B alloy, and the influence of tool offset on microstructures and mechanical properties of the joints was studied. The results showed that preferred properties were obtained when Mg was placed in the Advancing Side (AS) and offset was positioned into Mg. The distribution of Al3Mg2 and Al12Mg17 intermetallic compounds (IMCs) could be improved with offset in a certain range. The tensile strength of the joints was elevated with the increase of the offset due to the superior distribution and diminished size of IMCs, and when the offset was 1.5 mm, the joint strength reached the maximum value of 107 MPa. The microhardness of the stirring zone decreased with the increased offset.

2018 ◽  
Vol 14 (3) ◽  
pp. 1-11 ◽  
Author(s):  
Samir Ali Amin ◽  
Mohannad Yousif Hanna ◽  
Alhamza Farooq Mohamed

Bobbin friction stir welding (BFSW) is a variant of the conventional friction stir welding (CFSW); it can weld the upper and lower surface of the work-piece in the same pass. This technique involves the bonding of materials without melting. In this work, the influence of tool design on the mechanical properties of welding joints of 6061-T6 aluminum alloy with 6.25 mm thickness produced by FSW bobbin tools was investigated and the best bobbin tool design was determined. Five different probe shapes (threaded straight cylindrical, straight cylindrical with 3 flat surfaces, straight cylindrical with 4 flat surfaces, threaded straight cylindrical with 3 flat surface and threaded straight cylindrical with 4 flat surfaces) with various dimensions of the tool (shoulders and pin) were used to create the welding joints. The direction of the welding process was perpendicular to the rolling direction for aluminum plates. Tensile and bending tests were performed to select the right design of the bobbin tools, which gave superior mechanical properties of the welded zone.  The tool of straight cylindrical with four flats, 8 mm probe and 24 mm shoulders diameter gave better tensile strength (193 MPa), elongation (6.1%), bending force (5.7 KN), and welding efficiency (65.4%) according to tensile strength.     


2021 ◽  
Vol 23 (4) ◽  
pp. 140-154
Author(s):  
Tatiana Kalashnikova ◽  
◽  
Vladimir Beloborodov ◽  
Kseniya Osipovich ◽  
Andrey Vorontsov ◽  
...  

Introduction. Friction stir welding and processing are almost identical processes of severe plastic deformation at elevated temperatures. These technologies differ mainly in the purpose of its use: the formation of a hardened surface layer or producing a welded joint. However, it is known that both during welding and during processing of heavy gauge workpieces temperature gradients occur. As a result, the conditions of adhesive interaction, material plastic flow, and the formation of the stir zone change as compared to thin-sheet workpieces with fundamentally different heat dissipation rates. In this connection, the purpose of the work is to determine the regularities of the structure formation and stability of the mechanical properties in different directions in the material of 35-mm-thick aluminum-magnesium alloy samples produced by friction stir welding/processing. Research Methodology. The technique and modes of friction stir welding and processing of AA5056 alloy workpieces with a thickness of 35 mm are described. Data on the equipment used for mechanical tests and structural research are given. Results and discussion. The data obtained show the excess mechanical properties of the processing zone material over the base metal ones in all studied directions. Material structure heterogeneities after friction stir welding/processing of heavy gauge workpieces have no determining effect on the stir zone properties. At the same time, there is no clear correlation between the tensile strength values and the load application direction, nor is there any significant difference in mechanical properties depending on the location of the samples inside the stir zone. The average ultimate tensile strength values in the vertical, transverse, and longitudinal directions are 302, 295 and 303 MPa, respectively, with the yield strength values of 155, 153 and 152 MPa, and the relative elongation of 27.2, 27.5, 28.7 %.


2014 ◽  
Vol 496-500 ◽  
pp. 110-113
Author(s):  
Dong Gao Chen ◽  
Jin He Liu ◽  
Zhi Hua Ma ◽  
Wu Lin Yang

The7A05 aluminum alloy of the 10mm thickness was welded by the friction stir welding. The microstructure and mechanical Properties of the welded joint was researched by the optical microscope, etc. The results showed: the microstructure of the weld nugget zone and the thermal mechanically affected zone were refined as the welding speed increasing when the rotate speed is constant. As the welding speed increasing the strength of extension of the welded joint is increasing at first and then stable basically. but the yield strength had no obvious change.


2014 ◽  
Vol 590 ◽  
pp. 187-191 ◽  
Author(s):  
Chuan Hong Luo ◽  
Wei Ping Peng ◽  
Ting Chen ◽  
Fei Bo Dong

The joint of 2219-T6 aluminum alloy plate was obtained by friction stir welding, and the microstructures and mechanical properties of the joint were investigated. The causes of the weakened joint strength in friction stir welding were analyzed and summarized correspondingly. The tensile properties show that the transverse tensile strength of the joint can reach about 70% of the base metal. Through the heat treatment of recrystallization with high temperature and at short time, the joint can restore the ductility and eliminate the softening, which will improve the performance in mechanical intensity of the joint.


Sign in / Sign up

Export Citation Format

Share Document