Microhardness and Microstructural Studies on Underwater Friction Stir Welding of 5052 Aluminum Alloy

2017 ◽  
Author(s):  
Srinivasa Rao Pedapati ◽  
Dhanis Paramaguru ◽  
Mokhtar Awang
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Plate Thickness ◽  
Base Material ◽  
Friction Stir ◽  
Underwater Friction Stir Welding ◽  
Void Area ◽  
Average Size ◽  
Microstructural Studies

As compared to normal Friction Stir Welding (FSW) joints, the Underwater Friction Stir Welding (UFSW) has been reported to be obtainable in consideration of enhancement in mechanical properties. A 5052-Aluminum Alloy welded joints using UFSW method with plate thickness of 6 mm were investigated, in turn to interpret the fundamental justification for enhancement in mechanical properties of material through UFSW. Differences in microstructural features and mechanical properties of the joints were examined and discussed in detail. The results indicate that underwater FSW has reported lower hardness value in the HAZ and higher hardness value in the intermediate of stir zone (SZ). The average hardness value of underwater FSW increases about 53% greater than its base material (BM), while 21% greater than the normal FSW. The maximum micro-hardness value was three times greater than its base material (BM), and the mechanical properties of underwater FSW joint is increased compared to the normal FSW joint. Besides, the evaluated void-area fraction division in the SZ of underwater FSW joint was reduced and about one-third of the base material (BM). The approximately estimated average size of the voids in SZ of underwater FSW also was reduced to as low as 0.00073 mm2, when compared to normal FSW and BM with approximately estimated average voids size of 0.0024 mm2 and 0.0039 mm2, simultaneously.

Effect of Pre and Post Weld Heat Treatment on the Mechanical Properties of Friction Stir Welded AA6061-T6 Joint

2020 ◽  
Vol 17 (2) ◽  
pp. 7882-7889 ◽  
Author(s):  
J.C. Verduzco Huarez ◽  
R. Garcia Hernandez ◽  
G. M. Dominguez Almaraz ◽  
J.J. Villalón López
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Research Work ◽  
Base Material ◽  
Welding Process ◽  
Post Weld Heat Treatment ◽  
Friction Stir

This research work focuses on the study of the improvement of mechanical properties, specifically the tensile strength of 6061-T6 aluminum alloy on prismatic specimens with 9.5 mm thickness that has been subjected to friction stir welding process and two heat treatments; solubilized and aging before or after the welding process. Three cases studied and evaluated were, welding of the base material without heat treatment (BMW), solubilized heat treatment and partial aging of the base material before welding (HTBW), and heat treatment of solubilized and aging of the base material after welding (HTAW). The obtained results show an increase of about 10% (20 MPa) of tensile strength for the HTBW process, compared to BMW case. In addition, for the case of HTAW, the obtained tensile resistance presents a joint efficiency of 96%, which is close to the tensile strength of the base material (»310 MPa).

Friction stir butt-lap welding of A7N01P-T4 aluminum alloy: Efforts to mitigate defects and the resultant mechanical properties

2020 ◽  
Vol 234 (6) ◽  
pp. 873-880
Author(s):  
Rongzheng Xu ◽  
Zhicheng Wei ◽  
Jianbo Jiang ◽  
Yanxi Hou ◽  
Hui Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Rotational Speed ◽  
Plate Thickness ◽  
Base Material ◽  
Friction Stir ◽  
Tool Geometries ◽  
Tool Offset ◽  
Lap Welding

Butt-lap configuration of aluminum alloys was friction stir welded under various tool offsets, rotational speeds, and tool geometries. The tool offset was introduced to mitigate the inherent retreating side hook. As the probe was placed inwards, the retreating side hook was mitigated, but a severe S-line was formed. Since the inherent retreating side hook was difficult to further mitigate, the S-line was selected to be mitigated by increasing the rotational speed. But an excessive rotational speed (2000 r/min) could cause a severe upward-bending retreating side hook, which decreased the effective plate thickness. Subsequently, two-section stepped probes were employed to mitigate the defects. The S-line and retreating side hook were both mitigated and its ultimate tensile strength (369 MPa) reached 91% of the base material.

Effect of tool feed on mechanical properties of butt joints during friction welding with mixing of aluminum alloys

2020 ◽  
pp. 65-70
Author(s):  
A.N. Feofanov ◽  
V.V. Ovchinnikov ◽  
A.M. Gubin
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
Friction Welding ◽  
Base Material ◽  
Butt Joints ◽  
Structure Defects ◽  
Friction Stir ◽  
Time Parameters

Friction stir welding of butt joints of aluminum alloys is considered. It is experimentally determined, that when temperature and time parameters are violated, defects in the form of discontinuities are localized at the boundary of the weld and the base metal, due to incompatibility of deformations of the weld metal and the adjacent base material. Keywords friction welding with stirring, aluminum alloy, mode parameters, structure, defects, strength. [email protected]

A Study on Grain Size, Mechanical Properties and First Mode of Metal Transfer in Underwater Friction Stir Welded AA5052-O

2018 ◽  
Vol 775 ◽  
pp. 466-472 ◽  
Author(s):  
K. Tejonadha Babu ◽  
S. Muthukumaran ◽  
C. Bharat Kumar
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Metal Transfer ◽  
Welding Parameters ◽  
Friction Stir ◽  
Second Mode ◽  
Underwater Friction Stir Welding

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.

A Study on Influence of Underwater Friction Stir Welding on Microstructural, Mechanical Properties and Formability in 5052-O Aluminium Alloys

2019 ◽  
Vol 969 ◽  
pp. 27-33
Author(s):  
K. Tejonadha Babu ◽  
S. Muthukumaran ◽  
C.H. Bharat Kumar ◽  
C. Sathiya Narayanan
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Grain Refinement ◽  
Hardness Test ◽  
Friction Stir ◽  
Underwater Friction Stir Welding ◽  
Save Energy ◽  
Solid State Joining ◽  
Joining Process

Friction stir welding (FSW), a solid-state joining process is extensively using in the welding of aluminum alloy sheets. In order to save energy and reduce emission, lightweight materials like aluminum alloys were introduced into steel car body, which requires the development of effective joining processes. In the present study, welding was carried out in two different conditions, in the air (CFSW) and underwater (UWFSW) at various welding speeds to weld 5052-O aluminum alloy sheets. The effect of UWFSW on microstructural developments, mechanical properties, and formability was evaluated and compared. Grain refinement is an important opportunity to improve the mechanical properties of FS welds. Considerable grain refinement was obtained in UWFSW joints, which is smaller than that in the CFSW joints. The results indicated an increase in tensile strength, hardness, the percentage of elongation, and formability of UWFSW weld sheets. The results of the tensile test, hardness test, microstructure and fractography as in good correlation with improved properties.

scholarly journals Effect of Applied Pressure on the Mechanical Properties of 6061 Aluminum Alloy Welded Joints Prepared by Friction Stir Welding

2017 ◽  
Vol 7 (3) ◽  
pp. 1619-1622
Author(s):  
J. A. Al-jarrah ◽  
A. Ibrahim ◽  
S. Sawlaha
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Axial Force ◽  
Welded Joints ◽  
Applied Pressure ◽  
Base Material ◽  
Surface Appearance ◽  
6061 Aluminum Alloy ◽  
Friction Stir

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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