scholarly journals Friction-Stir Welding of a Wrought Al-Si-Mg Alloy in As-Fabricated and Heat-Treatment States

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 861
Author(s):  
Chunxia Wang ◽  
Hongbo Cui ◽  
Xin Tang ◽  
Kezhun He
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Solution Treatment ◽  
Base Material ◽  
Welding Process ◽  
Age Hardening ◽  
Weld Strength ◽  
Friction Stir ◽  
Joint Efficiency ◽  
Al Matrix

A wrought Al-11.3Si-0.6Mg alloy under hot extrusion (T1), solution treatment (T4), and solution treatment + artificial aging (T6) states were friction stir welded at welding speed of 100 mm/min and rotation rate of 800 rpm. The effect of prior heat-treatment on the microstructure and mechanical properties of the welds were investigated. The results show that the microstructures of the nugget zones have little dependence on the initial states of the base material. In the nugget zones, complete recrystallized structures with equaxied grains in the Al matrix were formed under all conditions. The Si particles in the nugget zones are almost unchanged compared with those of their base materials (BMs) in the three states. In contrast, the joint efficiency of the obtained welds was very sensitive to the initial material condition. The joint efficiency under the T1 state is more than 90% due to the fact that the microstructure is almost unchanged, except for the slight coarsening of the Al matrix grains and some of the Mg2Si phases during the friction stir welding process. However, the joint efficiency in the T4 and T6 conditions is only 77.22% and 62.03%, respectively. The relatively low weld strength in the T4 and T6 conditions is due to the elimination of the solid solution strengthening and age hardening effects during friction stir welding. The hardness distributions along the cross section of joints are all W-shaped under T1, T4, and T6 conditions.

Effect of Strain Hardening on the Joint Efficiency of an Al-Mg-Sc-Zr Alloy Subjected to Friction Stir Welding

2014 ◽  
Vol 922 ◽  
pp. 463-468
Author(s):  
Sergey Malopheyev ◽  
Vladislav Kulitskiy ◽  
Sergey Mironov ◽  
Daria Zhemchuzhnikova ◽  
Rustam Kaibyshev
Keyword(s):  
Friction Stir Welding ◽  
Strain Hardening ◽  
Initial Conditions ◽  
Welding Process ◽  
Weld Strength ◽  
Friction Stir ◽  
Joint Efficiency ◽  
Cold Rolled ◽  
Cold Worked ◽  
Hot Rolled

The microstructure and mechanical properties of friction stir welded Al-5.4Mg-0.2Sc-0.1Zr alloy were studied. Defect-free welds were produced in hot extruded, hot rolled and cold rolled initial conditions. Friction stir welding led to the formation of ultrafine-grained structure in stir zone that contributes to overall strengthening. Coherent Al3(Sc,Zr) dispersoids retain partially during welding process that provides a joint efficiency close to 100% in the hot extruded and hot rolled materials. In the cold-rolled state the joint efficiency was found to be only 64%. The relatively low weld strength of the cold rolled material was attributed to the elimination of strain hardening due to the formation of recrystallized structure. It was shown that full strength weld can be achieved in semi-finished products of Al-Mg-Sc alloys in cold-worked and stabilized states being equal to H323 and H341 tempering by friction stir welding.

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).

The Effect of Stirring Tool Surface Condition on Wear Characteristics in Friction Stir Welding (FSW) Process

2021 ◽  
Vol 880 ◽  
pp. 57-62
Author(s):  
Normariah Che Maideen ◽  
Salina Budin ◽  
Koay Mei Hyie ◽  
Nor Azirah Mohd Fohimi
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Surface Condition ◽  
Welding Process ◽  
Wear Characteristics ◽  
Rotating Speed ◽  
Friction Stir ◽  
Ticn Coating ◽  
Tool Surface

Stirring tool is one of the important factor that contribute to the successful of Friction Stir Welding (FSW). Role of tool, is to heat the welding zone and stir the material along the process. Many studies have been conducted by other researchers to improve the performance of stirring tool. Similar to this work, it is aimed to investigate and analyze the effect of stirring tool surface condition on wear characteristics in friction stir welding process. Four tools have been fabricated with pre-determined surface condition. Tool 1: H13 without heat treatment and without coating. Tool 2: H13 with heat treatment only. Tool 3: H13 with TiCN coating only and Tool 4: H13 with heat treatment and with TiCN coating. Friction stir welding was performed to test and verify the performance of fabricated tools. Process parameter used are 1270 RPM for rotating speed while 218 mm/min for welding speed. From the result, Tool 4 performed better in terms of physical wear as well as wear rate.

Effects of Post Weld Heat Treatments (PWHT) on Friction Stir Welded AA2219-T87 Joints

2017 ◽  
Author(s):  
Mohammad W. Dewan ◽  
Muhammad A. Wahab ◽  
Khurshida Sharmin
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Yield Strength ◽  
Solution Treatment ◽  
Welding Process ◽  
Alloying Elements ◽  
Age Hardening ◽  
Experimental Program ◽  
Friction Stir ◽  
Aging Period

Friction Stir Welding (FSW) offers significantly better performance on aluminum alloy joints compared to the conventional fusion arc welding techniques; however, plastic deformation, visco-plastic flow of metals, and complex non-uniform heating cycles during FSW processes, result in dissolution of alloying elements, intrinsic microstructural changes, and post-weld residual stress development. As a consequence, about 30% reduction in ultimate strength (UTS) and 60% reduction in yield strength (YS) were observed in defect-free, as-welded AA2219-T87 joints. PWHT is a common practice to refine grain-coarsened microstructures which removes or redistributes post-weld residual stresses; and improves mechanical properties of heat-treatable welded aluminum alloys by precipitation hardening. An extensive experimental program was undertaken on PWHT of FS-welded AA2219-T87 to obtain optimum PWHT conditions and improvement of the tensile properties. Artificial age-hardening (AH) helped in the precipitation of supersaturated alloying elements produced around weld nugget area during the welding process. As a result, an average 20% improvement in YS and 5% improvements in UTS was observed in age-hardened (AH-170°C-18h) specimens as compared to AW specimens. To achieve full benefit of PWHT, solution-treatment followed by age-hardening (STAH) was performed on FS-welded AA2219-T87 specimens. Solution-treatment (ST) helps in the grain refinement and formation of supersaturated precipitates in aluminum alloys. Age-hardening of ST specimens help in the precipitation of alloying elements around grain boundaries and strengthen the specimens. Optimum aging period is important to achieve better mechanical properties. For FS-welded AA2219-T87 peak aging time was 5 hours at 170°C. STAH-170°C -5h treated specimens showed about 78% JE based on UTS, 61% JE based on yield strength, and 36% JE based on tensile toughness values of base metal.

Microstructural Characterization and Mechanical Properties in Friction Stir Welding of AA6061 and AA6101 Aluminum Alloys

2021 ◽  
Vol 40 ◽  
pp. 1-11
Author(s):  
Gagandeep Singh ◽  
Khushdeep Goyal ◽  
Baljinder Ram ◽  
Bal Krishan
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Friction Stir ◽  
Tool Pin Profile ◽  
Fine Grain ◽  
Metal Plates ◽  
Frictional Forces ◽  
Tool Pin

In this research paper, two different metal plates of aluminum alloy viz. AA6061 and AA6101 were welded with friction stir welding process. Round tool and square tool pin profiles were used to weld the alloys. Weld microstructures, hardness, and tensile properties were evaluated in as-welded condition. The tensile strength of the joints fabricated with round tool pin profile were lower than the square tool pin profile because of the pulsating effect, in square tool pin profile this effect was produced along with the higher frictional forces. The micro-hardness of friction stir zone was higher than the base material due to active recrystallization occurrence which resulted in fine grain size in case of weld joint with round pin profile. Microstructure indicated uniformly distribution of materials with minimum heat affected zone and dense welded zone without any defects.

Utilization of a Curly Toolpath in Friction Stir Welding

2021 ◽  
Vol 1165 ◽  
pp. 15-29
Author(s):  
Tyler J. Grimm ◽  
Derek Shaffer ◽  
Ihab Ragai
Keyword(s):  
Friction Stir Welding ◽  
Process Parameters ◽  
Tool Path ◽  
Base Material ◽  
The Other ◽  
Weld Strength ◽  
Mechanical Mixing ◽  
Material Interface ◽  
Friction Stir ◽  
High Level

Friction stir welding (FSW) is an advanced solid-state metal joining technique. This operation fuses adjacent materials through the use of a non-consumable, rotating tool, which is plunged into and travels along the seam of the materials. Since this joining method avoids the bulk melting of the base materials, it is considered a relatively energy efficient process. Additionally, the strength of the base material is often improved due to significant grain refinement resulting from the stirring action of the tool at relatively low temperatures. Another inherent benefit is that the joint thickness, which is dependent on the length of the pin, can be much greater than most other joining processes and can also be well controlled. This joining method conventionally relies on the friction at the tool-base material interface to stir materials. Other research has implemented complex tooling to mechanically enhance this stirring action. However, these tools are often expensive, requiring a high level of capability within industry. In order to improve the weld strength of FSW, a novel toolpath is utilized which significantly improves the mechanical mixing of the constituent materials without the need for complex tooling, such as tools with threaded pins. The path currently investigated forms a curl as it travels both perpendicular and parallel to the joint. This motion is used to extend the stirring action of the tool to regions outside the immediate joint area. It was found that this tool path is effective in improving weld strength under specific process parameters. Constraining the tool's axis normal to the workpiece surface resulted in a void that was formed in the majority of tests; however, this void was eliminated with modification of the process parameters. An uneven distribution of heat was recognized within this testing in which one side of the joint was hotter than the other. This observation may be used in future studies to perform multi-material joining where it is often necessary to increase the temperature of one material more than the other.

scholarly journals A Study on the Friction Stir Welding Experiment and Simulation of the Fillet Joint of Extruded Aluminum Material of Electric Vehicle Frame

2020 ◽  
Vol 10 (24) ◽  
pp. 9103
Author(s):  
Hwanjin Kim ◽  
Kwangjin Lee ◽  
Jaewoong Kim ◽  
Changyeon Lee ◽  
Yoonchul Jung ◽  
...  
Keyword(s):  
Residual Stress ◽  
Friction Stir Welding ◽  
Electric Vehicle ◽  
Manufacturing Process ◽  
Base Material ◽  
Welding Process ◽  
Inert Gas ◽  
Measured Temperature ◽  
Friction Stir ◽  
Fillet Joint

In the existing automobile manufacturing process, metal inert gas (MIG) and tungsten inert gas (TIG) welding are mainly used. These welding methods are fusion welding, and the heat input in the welding area is very high. Therefore, the deformation of the base material is large, and the residual stress in the vicinity of the welded area is high, resulting in the problem of reduced mechanical strength. In this study, friction stir welding (FSW) was applied to the welding process of the structure constituting the battery frame of a newly developing electric vehicle to compensate for this problem. The welded part is the fillet joint of the side frame and the bottom frame, and experiments and numerical analysis were performed on the welding deformation and residual stress of the full frame structure. A specially manufactured angle head was used for friction stir welding of the fillet joint of extruded type aluminum, not the existing solid type. The optimum process was derived through experiments, and the temperature of the welding center was derived through test correlation between the value of measured temperature and the finite element model. The final deformation result was verified by comparing it with the measured value using a dial indicator. It is expected that the proposed thermal elasto-plastic analysis method will reduce the testing period and the cost of the manufacturing process and increase productivity.

scholarly journals Friction stir welding of new electronic packaging materials SiCp/Al composite with T-joint

2018 ◽  
Vol 38 (3) ◽  
pp. 352-359
Author(s):  
Zeng Gao ◽  
Jianguang Feng ◽  
Huanyu Yang ◽  
Jukka Pakkanen ◽  
Jitai Niu
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Welding Process ◽  
Experimental Results ◽  
Homogeneous Distribution ◽  
Welding Parameters ◽  
Matrix Composites ◽  
Friction Stir ◽  
Lower Temperature ◽  
Gas Tightness

Using friction stir welding, the electronic container box and lid made from aluminium matrix composites with reinforcement of SiC particle (15 vol% SiCp/Al-MMCs) was welded successfully with T-joint. The temperature distribution of box during the process, mechanical property and microstructure of the joint as well as gas tightness of welded box was investigated. The experimental results indicated that the satisfactory T-joint can be obtained under appropriate friction stir welding parameters. During the welding process, the bottom center, which was used to place the electronic component, reached a quite lower temperature of 100°C. That can ensure safety of components in the box. After the welding process, the microstructure in stir zone was better than in base material due to the refining and homogeneous distribution of the SiC particles. The experimental results showed that the electronic container box after friction stir welding had gas tightness. The He-leakage rate was under 10-8 Pa•m3/s.

The Rotational Extrusion Alloying

2013 ◽  
Vol 664 ◽  
pp. 521-524
Author(s):  
Wei Ping Xu ◽  
Li Ming Ke ◽  
Li Xing
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Low Temperature ◽  
High Speed ◽  
Welding Process ◽  
Stable Phase ◽  
Dissimilar Metals ◽  
Friction Stir ◽  
Pole Figures ◽  
Extrusion Technology

The Rotating Extrusion Alloying (REA) is a process which combined friction stir welding process and extrusion technology. In the REA process, dissimilar metals are mixed, cracked, and subjected to high speed, severe pressing deformation, and therefore rapidly alloy at a low temperature. The result shows that REA technology can be alloyed Al-Ti material. Its phases are mainly composed of Al and Al3Ti, which are distributed more evenly in the aluminum. After heat treatment, its phases’ types and pole figures have no significant change, but there is a trend of transition to the non-equilibrium stable phase. Small-angle grain boundaries decrease or even disappear.

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