scholarly journals Effect of Copper Donor Material Assisted Friction Stir Welding of AA6061-T6 Alloy On Downward Force, Microstructure, And Mechanical Properties

2021 ◽  
Author(s):  
Srinivasa Bhukya ◽  
Zhenhua Wu ◽  
Joseph Maniscalco ◽  
Abdelmageed Elmustafa
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Tensile Failure ◽  
Welding Parameters ◽  
Micro Hardness ◽  
Friction Stir ◽  
Donor Material ◽  
Microstructure And Mechanical Properties ◽  
Effect Of Copper ◽  
Increase Tool Life

Abstract In this research, Copper (Cu) donor material assisted friction stir welding (FSW) of AA6061-T6 alloy was studied. Cu assisted FSW joints of AA6061-T6 alloy were prepared at a constant tool rotational rate of 1400 rpm and various welding speeds at 1 mm/s and 3 mm/s. The Cu donor material of different thickness (i.e., 20%, 40%, and 60%) with respect to the workpiece thickness was selected to assist the FSW joining at the plunge stage. It is observed that the downward force generated in the FSW process was gradually decreased after introducing Cu donor material with incremental thicknesses with respect to workpiece at the plunge stage. Post-weld analysis was characterized in terms of microstructure, and mechanical properties. The results of microstructure analysis at the stir zone (SZ) show the formation of finer grains due to dynamic recrystallization and plastic deformation. Micro-hardness tests reveal that the hardness decreased from the base metal (BM) to the SZ across the heat affected zone (HAZ) and thermo-mechanically affected zone (TMAZ). The lowest value of hardness appeared in the TMAZ and HAZ where tensile failure occurs. With increasing welding speed, the average hardness in the SZ decreased due to lower heat input and faster cooling rate. Tensile test plots show no significant change in ultimate tensile strength with or without Cu donor material. Fractography of tensile tested samples shows both ductile and brittle like structure for given welding parameters. This proposed work of FSW with Cu donor material is promising to increase tool life due to the decrement of the downforce during plunge and throughout the welding stage. Meanwhile, the inclusion of donor material did not compromise the weld quality in terms of the mechanical properties and micro-hardness.

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.

Evaluation of Microstructure and Mechanical Properties for Friction Stir Welding of Aluminium HE-30 Plates

2019 ◽  
Vol 969 ◽  
pp. 720-726
Author(s):  
Ajay Kumar Revelly ◽  
B. Rajkumar ◽  
V. Swapna
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Rotational Speed ◽  
Weld Zone ◽  
Tool Geometry ◽  
Welding Parameters ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Non Destructive

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.

On the role of input welding parameters on the microstructure and mechanical properties of Al6061-T6 alloy during the friction stir welding: Experimental and numerical investigation

2021 ◽  
pp. 146442072110444
Author(s):  
Behrouz Bagheri ◽  
Farzaneh Sharifi ◽  
Mahmoud Abbasi ◽  
Amin Abdollahzadeh
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Friction Stir Welding ◽  
Welding Process ◽  
Welding Parameters ◽  
Optimal Parameters ◽  
Rotating Speed ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Material Element

The Taguchi method was employed to find the optimum values of friction stir welding parameters including welding speed, rotating speed, and tilt angle for joining AA6061-T6 aluminum alloys. The combined influences of these parameters were entirely analyzed. Statistical outcomes were investigated by the study of variances and signal-to-noise ratios. A Coupled Eulerian and Lagrangian technique is implemented to simulate and verify the optimal parameters during the friction stir welding. To verify results, a comparison between the welding process under optimized parameters with experimental and non-optimized parameters was simulated for the friction stir welding process. The material flow, strain rate, thermal behaviors, and mechanical properties of samples fabricated with optimal welding parameters are higher than those produced from the non-optimal parameters. It was also concluded that the grain size of the stir zone under optimal welding parameters (6–8 µm) is finer than that of non-optimal welding parameters (11–13 µm). Low uniform distribution of material element and coarse microstructure were some of the results of welding with non-optimized parameters. Based on residual stress analysis, the application of optimal joining conditions can decrease the peak tensile residual stress by about 38.3%. The much desirable results obtained in terms of microstructure and mechanical properties could be of great significance to the welding industry.

Influence of post welding heat treatment on the microstructure and mechanical properties of friction stir welding joint of AZ31 Mg alloy

2021 ◽  
pp. 095440892199762
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Tensile Failure ◽  
Mg Alloy ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
Az31 Mg Alloy

At present, magnesium alloys are extensively used in numerous applications due to their light weight and better characteristics. Welding of magnesium alloys is regarded as one of the most complex phenomena in various industries. The friction stir welding of magnesium alloys has encouraged abundant scientific and industrial interest as it has the potency to form a good quality joint. Post welding heat treatment is an appropriate process to further improve the properties or performance of FSW joints. Therefore, the present work aims to join AZ31 Mg alloy plates by friction stir welding, and microstructural and mechanical properties of the joint have been examined. Furthermore, the consequence of post welding heat treatment on the microstructure and mechanical properties of FSW joint has been evaluated. Tensile strength and elongation of FSW joint were about 145.4 ± 4.9 MPa and 9.5 ± 0.9%, respectively. It was found that post welding heat treatment was beneficial in homogenizing grains and to enhance mechanical properties. Tensile strength and elongation of the joint were improved by 4.74% and 15.78% respectively after PWHT. The highest microhardness of stir zone decreased about 6.84% (73 Hv to 68 Hv) after heat treatment and hardness pattern of weld became relatively smooth. Toughness of PWHT joint was 4.5 ± 0.17 Joules. The mode of tensile failure of as-welded and PWHT joint was ductile.

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