Effects of bottom plate in friction stir welding of AA6061-T6

2020 ◽  
Vol 118 (1) ◽  
pp. 108
Author(s):  
M.A. Vinayagamoorthi ◽  
M. Prince ◽  
S. Balasubramanian
Keyword(s):  
Mechanical Properties ◽  
Axial Load ◽  
Weld Zone ◽  
Welding Process ◽  
Bottom Plate ◽  
Welding Parameters ◽  
Nugget Zone ◽  
Friction Stir ◽  
Weld Joints ◽  
Fine Grain

The effects of 40 mm width bottom plates on the microstructural modifications and the mechanical properties of a 6 mm thick FSW AA6061-T6 joint have been investigated. The bottom plates are placed partially at the weld zone to absorb and dissipate heat during the welding process. An axial load of 5 to 7 kN, a rotational speed of 500 rpm, and a welding speed of 50 mm/min are employed as welding parameters. The size of the nugget zone (NZ) and heat-affected zone (HAZ) in the weld joints obtained from AISI 1040 steel bottom plate is more significant than that of weld joints obtained using copper bottom plate due to lower thermal conductivity of steel. Also, the weld joints obtained using copper bottom plate have fine grain microstructure due to the dynamic recrystallization. The friction stir welded joints obtained with copper bottom plate have exhibited higher ductility of 8.9% and higher tensile strength of 172 MPa as compared to the joints obtained using a steel bottom plate.

Experimental investigation and optimization of mechanical properties on combination of higher and lower strength of aluminum alloys

2021 ◽  
pp. 095440892110606
Author(s):  
C Ganesan ◽  
K Manonmani
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Welding Speed ◽  
Rotational Speed ◽  
Axial Load ◽  
Welding Process ◽  
Process Parameter ◽  
Nugget Zone ◽  
Friction Stir ◽  
Tool Pin

Friction stir welding is a high potential technology for joining similar and dissimilar aluminum materials, utilized extensively in aerospace and automotive industrial applications to eradicate the problems like hot cracking, porosity, element loss, etc. due to the fusion welding process. This Research addresses the joining of two dissimilar materials of AA 5754 – H32 and AA 8090T6511 – Al-Li and their mechanical properties analysis with the effects of friction stir welding process parameters like tool rotational speed, welding speed and axial load on weld nugget zone formation quality. The significant roles of different tool pin profiles are also emphasized. A mathematical modeling equation was formed by using regression analysis to optimize the process parameter and found the best tool pin profile for defect-free weld nugget zone and higher tensile and hardness properties. This research also portrays the contribution of various pin profiles and each process parameter on the ultimate tensile strength by response surface methodology. The results indicate that the defect-free weld joints are observed with 1800 r/min of rotational speed, welding speed of 15 mm min−1 and 8.5 kN of axial load with hexagonal pin profile.

scholarly journals Effect of process parameters on mechanical properties of AA5052 joints using underwater friction stir welding

2020 ◽  
Vol 14 (1) ◽  
pp. 6259-6271
Author(s):  
Srinivasa Rao Pedapati ◽  
Dhanish Paramaguru ◽  
Mokhtar Awang ◽  
Hamed Mohebbi ◽  
Sharma V Korada
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Process Parameters ◽  
Welding Process ◽  
Welding Parameters ◽  
Fracture Characterization ◽  
Friction Stir ◽  
Weld Joints ◽  
Underwater Friction Stir Welding

Underwater Friction Stir Welding (UFSW) is a solid-state joining technique which uses a non-consumable tool to weld metals. The objective of this investigation is to evaluate the mechanical properties of the AA5052 Aluminium alloy joints prepared by UFSW. The effect of different type of welding tools and welding parameters on the weld joint properties are studied. Square, tapered cylindrical and taper threaded cylindrical type of welding tools have been used to produce the joints with the tool rotational speed varying from 500 rpm to 2000 rpm while the welding speed varying from 50 mm/min to 150 mm/min. Tensile strength, micro-hardness distribution, fracture features, micro-and macrostructure of the fabricated weld joints have been evaluated. The effect of welding process parameters that influences the mechanical properties and fracture characterization of the joints are explained in detail. A maximum Ultimate Tensile Strength (UTS) value of 222.07 MPa is attained with a gauge elongation of 14.78%. Microstructural evaluation revealed that most of the fracture are found on the thermal mechanically affected zone (TMAZ)adjacent to the weld nugget zone (WNZ) due to bigger grain sizes. It is found that most of the joints exhibit ductile characteristics in failure. Fractography analysis has been used to find the behavior of weld joints in failure.

Influence of Tool Rotational Speed on the Mechanical Properties of Friction Stir Welded Al-Cu-Li Alloy

2016 ◽  
Vol 857 ◽  
pp. 228-231
Author(s):  
Ho Sung Lee ◽  
Ye Rim Lee ◽  
Kyung Ju Min
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Space Shuttle ◽  
Welding Process ◽  
High Strength ◽  
Fusion Welding ◽  
Welding Parameters ◽  
Friction Stir ◽  
Mechanical And Microstructural Properties ◽  
Tool Rotation

Aluminum-Lithium alloys have been found to exhibit superior mechanical properties as compared to the conventional aerospace aluminum alloys in terms of high strength, high modulus, low density, good corrosion resistance and fracture toughness at cryogenic temperatures. Even though they do not form low-melting eutectics during fusion welding, there are still problems like porosity, solidification cracking, and loss of lithium. This is why solid state friction stir welding is important in this alloy. It is known that using Al-Cu-Li alloy and friction stir welding to super lightweight external tank for space shuttle, significant weight reduction has been achieved. The objective of this paper is to investigate the effect of friction stir tool rotation speed on mechanical and microstructural properties of Al-Cu-Li alloy. The plates were joined with friction stir welding process using different tool rotation speeds (300-800 rpm) and welding speeds (120-420 mm/min), which are the two prime welding parameters in this process.

scholarly journals Microstructure and Mechanical Properties of Friction Stir Welded Joint of an Aluminum Alloy Sheet 6005A-T4

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1152 ◽  
Author(s):  
Xiaofei Sheng ◽  
Kai Li ◽  
Wenke Wu ◽  
Yong Yang ◽  
Yu Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Alloy Sheet ◽  
Welding Parameters ◽  
Indentation Hardness ◽  
Related Field ◽  
Friction Stir ◽  
Β Phase ◽  
Fine Grain ◽  
Equiaxed Grain ◽  
Micro Indentation

The 6005A-T6 alloy had been widely applied in rail transmit industry due to its combination properties of moderate strength, superior resistance to corrosion, and excellent extrusion plasticity. However, few reports were related to the 6005A-T4 alloy in spite of it also presenting considerable properties. In this work, we introduced the FSW method to investigate the weldability and mechanical properties of a thin plate aluminum 6005A-T4 to evaluate its potential application. Fully recrystallized microstructure was obtained in the nugget zone, characterized by equiaxed grain with a size of 2.2 μm under current welding parameters. The tensile strength can reach as high as 174 ± 2 MPa with the absence of β phase, which is equivalent to 83.8% of that of base metal. The dissolution of β phase will dramatically reduce the micro-indentation hardness down to as low as 58 HV0.2 and the fine grain, for example 2 μm in this work, will reversely raise this value up to 64 HV0.2. Our investigation provides some perspectives to understand weldability, mechanical properties of the 6005A-T4 alloy, and develop its further applications in the related field.

scholarly journals Incorporating oxygen-free copper to improve the microstructure and mechanical properties of friction-stir-welded joints for aluminum alloys

2018 ◽  
Vol 25 (6) ◽  
pp. 1219-1228
Author(s):  
Her-Yueh Huang ◽  
Chung-Wei Yang ◽  
Wen-Yao Deng
Keyword(s):  
Mechanical Properties ◽  
Rotation Speed ◽  
Welding Process ◽  
Weld Nugget ◽  
Nugget Zone ◽  
Friction Stir ◽  
Copper Particles ◽  
Dissimilar Metal ◽  
Tool Rotation ◽  
Traveling Speed

AbstractThe main objective of the present work was to establish a friction-stir-welding process to weld dissimilar metal joints on AA6082 and AA6066 aluminum alloy plates. Joints were made while varying tool rotation speed at a constant traveling speed and at the same time adding oxygen-free copper reinforcement inside the weld nugget for the purpose of analyzing the microstructural evolution and mechanical properties of the joint. Results showed that the morphology of the microstructure in the weld nugget changed significantly with rotation speed. Optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy analyses revealed that oxygen-free copper particles could be uniformly dispersed into the weld nugget because of higher rotation speeds. Because of the presence of reinforcement particles homogenously distributed inside the nugget zone, the mechanical properties, such as ultimate tensile strength and hardness of weld joint, were greatly improved.

scholarly journals Inter-relationship between microstructure evolution and mechanical properties in inertia friction welded 8630 low-alloy steel

2021 ◽  
Vol 21 (4) ◽  
Author(s):  
Amborish Banerjee ◽  
Michail Ntovas ◽  
Laurie Da Silva ◽  
Salaheddin Rahimi ◽  
Bradley Wynne
Keyword(s):  
Mechanical Properties ◽  
Alloy Steel ◽  
Weld Zone ◽  
Ductile Failure ◽  
Welding Parameters ◽  
Low Alloy Steel ◽  
Weld Joints ◽  
Dynamic Recrystallisation ◽  
Continuous Dynamic ◽  
Evolution Of Microstructure

AbstractThe evolution of microstructure and mechanical properties in AISI 8630 low-alloy steel subjected to inertia friction welding (IFW) have been investigated. The effects of three critical process parameters, viz. rotational speed, friction and forge forces, during welding of tubular specimens were explored. The mechanical properties of these weld joints, including tensile and Charpy V-notch impact were studied for determining the optimum welding parameters. The weld joints exhibited higher yield strength, lower hardening capacity and ultimate tensile strength compared to base metal (BM). The maximum strength and ductility combination was achieved for the welds produced under a nominal weld speed of ~ 2900–3100 rpm, the highest friction force of ~ 680–720 kN, and the lowest axial forging load of ~ 560–600 kN. The measured hardness distribution depicted higher values for the weld zone (WZ) compared to the thermo-mechanically affected zone (TMAZ), heat-affected zone (HAZ) and BM, irrespective of the applied welding parameters. The substantial increase in the hardness of the WZ is due to the formation of microstructures that were dominated by martensite. The observed microstructural features, i.e. the fractions of martensite, bainite and ferrite, show that the temperature in the WZ and TMAZ was above Ac3, whereas that of the HAZ was below Ac1 during the IFW. The fracture surface of the tensile and impact-tested specimens exhibited the presence of dimples nucleating from the voids, thus indicating a ductile failure. EBSD maps of the WZ revealed the formation of subgrains inside the prior austenite grains, indicating the occurrence of continuous dynamic recrystallisation during the weld. Analysis of crystallographic texture indicated that the austenite microstructure (i.e. FCC) in both the WZ and TMAZ undergoes simple shear deformation during IFW.

Influence of Friction Stir Welding Parameters on the Mechanical Properties of EN AW-7075 Weld Joints

2016 ◽  
Vol 835 ◽  
pp. 210-215
Author(s):  
Máté Nagy ◽  
Mária Behúlová
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Ultimate Strength ◽  
Base Material ◽  
High Strength ◽  
Welding Parameters ◽  
Micro Hardness ◽  
Friction Stir ◽  
Weld Joints ◽  
Welding Processes

The paper deals with the friction stir welding (FSW) of the high strength EN AW 7075-T651 aluminium alloy with the aim to analyze the influence of welding parameters on the mechanical properties of Al-weld joints. FSW represents relatively novel solid-state technology of material joining which can be successfully applied for welding of several metallic alloys including the high-strength aluminium alloys that are hard to weld by conventional fusion welding processes. In cooperation with VÚZ - PI SR Bratislava, nine experimental weld joints of samples with dimensions of 300 × 150 × 10 mm were prepared using the welding machine of the FSW-LM-060 type and different parameters of welding – the welding speed from 60 to 120 mm/min and the tool rotation rate from 600 to 1000 rpm in clockwise direction. The quality of weld joints was evaluated by static tensile tests and micro-hardness measurements. According to obtained results of tensile testing, the average values of ultimate strength of weld joints are by 32.2 % lower comparing with the ultimate strength of the base material. On the other hand, the ductility increased by 7.2 %. The highest micro-hardness of weld joints at the level of 129 HV was measured in thermo-mechanically affected zone on the retreating side.

scholarly journals Process Parameters Effect on Mechanical Properties and Fatigue Behavior of Friction Stir Weld AA6060 Joints

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
M. Longo ◽  
G. D’Urso ◽  
C. Giardini ◽  
E. Ceretti
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Fatigue Behavior ◽  
Welding Process ◽  
Fusion Welding ◽  
Fatigue Properties ◽  
Friction Stir Weld ◽  
Welding Parameters ◽  
Rotating Speed ◽  
Friction Stir

Friction stir welding (FSW) is the most remarkable welding technology that has been invented and developed in the last decade. It is a solid-state welding process in which a rotating tool is driven into the material and translated along the interface of two or more plates. This technology has been successfully used to join materials that are considered difficult to be welded by fusion welding methods. FSW has potentially significant applications in many industrial fields such as aerospace, automotive, and naval industry. Anyway, FSW technology requires a meticulous understanding of the process and consequent mechanical properties of the welds in order to be used in the production of high performance components. The present work deals with an experimental campaign aimed at the evaluation of the mechanical properties of AA6060 T6 friction stir welded joints. The butt joints obtained using two different tool geometries (standard and threaded) were performed by varying the welding parameters, namely, tool rotating speed and feed rate. The standard tool was a very simple device fabricated using AISI 1040 steel, with a flat shoulder and a cylindrical pin. The threaded tool was a more complex device based on two main components: a tool holder, with a flat shoulder, and a threaded probe obtained using a commercial thread forming tap. The quality of the joints was evaluated in terms of both tensile strength (UTS) and fatigue behavior. The study of axial pulsing fatigue properties required the fabrication of a specific testing device able to avoid parasite bending moments. In order to estimate the more efficient and effective tool type, the welding forces (axial and longitudinal) were also measured.

scholarly journals Repair Welding of the Tunnel Defect in Friction Stir Weld

2018 ◽  
Vol 37 (7) ◽  
pp. 675-681 ◽  
Author(s):  
Weipo Li ◽  
Zhimin Liang ◽  
Congwei Cai ◽  
Dianlong Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Weld Zone ◽  
Welding Process ◽  
Friction Stir Weld ◽  
Strength Increase ◽  
Repair Welding ◽  
Friction Stir ◽  
Longitudinal Residual Stress

AbstractThe tunnel defect formed in friction stir weld would dramatically push the mechanical properties of joints into deterioration. In this study, friction stir welding process was adopted to repair the joints of 7N01 aluminum alloy with tunnel defect. The effects of friction stir repair welding process on the microstructure and mechanical properties were comprehensively investigated. Microstructure of the repaired joints shows that the grain size in nugget zone decreases slightly while the recrystallization in the retreating side of thermo-mechanically affected zone is intensified as the joints are repaired. The microhardness of the repaired joints declined slightly compared with the defective joint. However, the yield strength and tensile strength increase and recover to the values of the joints free of defect. The longitudinal residual stress in weld zone increased remarkably as the repair times increase. Compared with the once repaired joint, yield strength and tensile strength of the twice repaired joint reduced slightly, and the throat thickness also reduced during the repeated repair welding process. Therefore, the times of repair welding applied should be limited actually.

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