Friction Stir Welding of SiCp/Al Composite and 2024 Al Alloy

2010 ◽  
Vol 638-642 ◽  
pp. 1500-1505 ◽  
Author(s):  
B.L. Xiao ◽  
Dong Wang ◽  
J. Bi ◽  
Z. Zhang ◽  
Z.Y. Ma
Keyword(s):  
Friction Stir Welding ◽  
Heat Affected Zone ◽  
Volume Fraction ◽  
Ring Structure ◽  
Al Alloy ◽  
Friction Stir ◽  
Sic Particles ◽  
Al Composite ◽  
Clad Layer ◽  
Tool Pin

6 mm thick SiCp/2009Al composite and 2024Al-T351 alloy plates were successfully joined by friction stir welding (FSW) with and without the tool pin offsetting to the 2024Al side (denoted as NOS and OS samples, respectively), producing defect-free joints. The SiC particles from the composite were distributed along a ring structure in the nugget and the volume fraction of the SiC particles decreased as the tool pin offset to the 2024Al side. The Al-clad layer on the 2024Al plate was aggregated on the retreating side of the nugget after FSW. For the OS sample, the Al formed a layer along the nugget boundary. The strength of the NOS sample reached up to 85% of the 2024Al alloy with the joint failing in the heat affected zone on the 2024Al side. The strength of the OS samples was 47% of the 2024Al alloy due to the aggregated Al layer on the retreating side of the nugget which decreased the strength of the joint.

Comparison of tool wear during friction stir welding of Al alloy and Al-SiC metal matrix composite

2021 ◽  
pp. 095440892110059
Author(s):  
Ashish Bist ◽  
JS Saini ◽  
Vikas Sharma
Keyword(s):  
Surface Roughness ◽  
Friction Stir Welding ◽  
Tool Wear ◽  
Rotational Speed ◽  
Welding Parameters ◽  
Aluminum Matrix Composites ◽  
Al Alloy ◽  
Friction Stir ◽  
Prolonged Contact ◽  
Tool Pin

Aluminum matrix composites have received considerable attention due to their high specific strength and specific stiffness, high hardness, and wear resistance along with being light in weight. These composites are preferably joined using friction stir welding process. The major concern in friction stir welding is the wear of the welding tool pin which is the backbone of the process. The wear is due to the prolonged contact between the tool and the harder reinforcements in the composite materials. The present work deals with the study of tool wear and its surface roughness with respect to different selected friction stir welding parameters such as rotational speed, transverse speed, length of weld, and different composition of Aluminum composite. It was found that the total amount of material removed from the tool and the surface roughness of the tool is in direct proportion to the rotational speed of the tool and the length of the weld but inversely proportional to the transverse rate. The increase in wt.% of SiC reinforcement leads to the higher tool wear but reduces the surface roughness of the tool.

scholarly journals Cladding of Advanced Al Alloys Employing Friction Stir Welding

2013 ◽  
Vol 554-557 ◽  
pp. 1014-1021 ◽  
Author(s):  
A.A. van der Stelt ◽  
T.C. Bor ◽  
H.J.M. Geijselaers ◽  
R. Akkerman ◽  
A.H. van den Boogaard
Keyword(s):  
Friction Stir Welding ◽  
Filler Material ◽  
Work Piece ◽  
Process Conditions ◽  
Pure Aluminium ◽  
Friction Stir ◽  
Clad Layer ◽  
Usual Process ◽  
Tool Pin

Friction stir welding (FSW) is a relatively new solid-state joining technology for metals. It shows no solidification-related joint imperfections which makes it utmost suitable for hard-to-weld highly alloyed aerospace aluminium grades, like AA 2xxx and AA 7xxx. These alloys are often cladded with a thin layer of pure aluminium for corrosion protection. Friction stir welding of such materials requires removal of the clad layer prior to welding to prevent weakening of the joint by the soft clad material. This leaves the welded region vulnerable to corrosion after the joining process. Post-weld restoration of the clad layer is required to restore the protective action of the clad layer and as such to enhance the life expectancy of the welded construction. In this work the deposition of thin layers of pure aluminium on AA 2xxx and AA 7xxx alloys is studied employing an innovative FSW tool. The tool shoulder is equipped with strategically placed internal channels that allow delivery of filler type of material into the weld zone. Depending on the channel architecture used, filler material can be deposited on top of the work piece surface and/or mixed with the work piece surface region. The cladding is done in the solid state avoiding many problems with solidification and interface reactivity often observed with other surface modification techniques, such as laser surface engineering, plasma spraying or casting. Here, the filler material is deposited on top of the work piece; the modified tool is not equipped with a tool pin. The work comprises an in depth study of the influence of process conditions on the microstructural changes in the underlying work piece and on the quality of the bonding of the clad material (99.5 % aluminium) to the work piece material. Apart from the usual process conditions, such as tool rotation speed, translation speed, down force and tool angle also the delivery pressure and rate of the filler supply system can be varied. The influence of the usual process conditions on the microstructure of the underlying work piece is similar to that observed with “traditional” FSW. Changes in hardness can be related to the amount of heat generated by the welding process. Shape and dimensions of the microstructural zones found are typical for welds made without a tool pin. The effect of the small amount of clad material deposited on top of the work piece on the temperature distribution is small. The amount of heat required to heat it up is negligible to the heat required to heat up the work piece and the tool. The quality of the bonded clad layer is dependent on the amount of heat and plastic deformation generated at the interfaces between the tool, the filler material and the work piece. Tool angle, tool shape and supply rate of the filler supply system determine the layer thickness.

scholarly journals Experimental investigations of friction stir welded AA6063 aluminum matrix composite

2018 ◽  
Vol 12 (4) ◽  
pp. 4127-4140
Author(s):  
Narinder Kaushik ◽  
Sandeep Singhal ◽  
Rajesh Rajesh ◽  
Pardeep Gahlot ◽  
B. N Tripathi
Keyword(s):  
Friction Stir Welding ◽  
Matrix Composite ◽  
Aluminum Matrix ◽  
High Speed Steel ◽  
Metal Composite ◽  
Composite Matrix ◽  
Friction Stir ◽  
Sic Particles ◽  
Tool Pin ◽  
The Impact

The advancement of friction stir welding for joining of aluminum alloys and aluminum centered matrix composite has replaced the traditional welding techniques. In this experimental study, AA6063/10.5wt%SiC composite has been produced by employing enhanced stir casting technique with the assistance of Mg metal powder. Specimen composite plates having thickness 6 mm were friction stir welded successfully. The impact of welding variables on mechanical and microstructural characteristics of weldments has been studied. The friction stir welding (FSW) was carried out at a rotation rate of tool of 1400 rpm with a tool transverse rate of 124 mm/min. A cylindrical tool fabricated of high-speed steel (HSS) with square pin shape has been used for FSW. The results revealed that the ultimate tensile strength of the welded joint was 163 MPa, which was very close to the strength of the as-cast composite matrix. The microstructural study showed the reason for higher joint strength and microhardness. The welded butt joint exhibited a change in the microstructure at various four welding zones which transforms the mechanical characteristics of welded joints has been due to the asymmetrical flow of material and thermal cycles around the pin. The intense stirring action of the tool pin during FSW cracked the SiC particles in the weld nugget.  In the weld region, a fine-grained structure and homogeneous dispersion of SiC particles have been observed. The micro porosities associated with the base metal composite matrix were eliminated after FSW.

scholarly journals Influence of material velocity on heat generation during linear welding stage of friction stir welding

2016 ◽  
Vol 20 (5) ◽  
pp. 1693-1701
Author(s):  
Alin Murariu ◽  
Darko Veljic ◽  
Dragana Barjaktarevic ◽  
Marko Rakin ◽  
Nenad Radovic ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Friction Stir Welding ◽  
Heat Generation ◽  
Welding Process ◽  
Slip Rate ◽  
Frictional Heat ◽  
Al Alloy ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Tool Pin

The heat generated during friction stir welding (FSW) process depends on plastic deformation of the material and friction between the tool and the material. In this work, heat generation is analysed with respect to the material velocity around the tool in Al alloy Al2024-T351 plate. The slip rate of the tool relative to the workpiece material is related to the frictional heat generated. The material velocity, on the other hand, is related to the heat generated by plastic deformation. During the welding process, the slippage is the most pronounced on the front part of the tool shoulder. Also, it is higher on the retreating side than on the advancing side. Slip rate in the zone around the tool pin has very low values, almost negligible. In this zone, the heat generation from friction is very low, because the material is in paste-like state and subjected to intensive plastic deformation. The material flow velocity around the pin is higher in the zone around the root of the pin. In the radial direction, this quantity increases from the pin to the periphery of the tool shoulder.

scholarly journals Temperature Based Optimization of Friction Stir Welding of AA 6061 Using GRA Synchronous With Taguchi Method

2021 ◽  
Author(s):  
Eyob Messele ◽  
Assefa Asmare Tsegaw
Keyword(s):  
Friction Stir Welding ◽  
Base Metal ◽  
Weld Zone ◽  
Welding Process ◽  
Quality Characteristic ◽  
Heat Transfer Analysis ◽  
Al Alloy ◽  
Welding Temperature ◽  
Friction Stir ◽  
Tool Pin

Abstract One of the recent novel joining mechanisms in the solid-state-welding process is Friction Stir Welding (FSW). The process is extensively used in joining similar and dissimilar materials as well. This research studied and found the optimum process parameters of FSW based on the temperature simulation results on a 5 mm 6061 Al alloy sheet with a butt joint configuration. Steady-state heat transfer analysis was performed using a transient thermal workbench to predict and identify the optimum parameters grounded on the simulation welding temperature result. The parameters are optimized using the hybrid Taguchi L9 orthogonal array and Grey relation analysis method with a larger is better quality characteristic. Mechanical properties of the weld joints' such as hardness and tensile strength, were studied at an ambient temperature. The result revealed that a higher rotational speed with a minimum traverse speed and taper threaded tool pin impart the optimum parameter settings. Analysis of variance (ANOVA) was carried out also to determine the effects of each process parameter. At a 95 % confidence interval, rotational and traverse speeds show significant characteristics. The joint efficiency reached 92.25% of the base metal at a maximum welding temperature. Additionally, the microstructure of the stir weld zone of the specimen was studied as well. Metallographic Characterization carried out using Scanning Electron Microscope (SEM) revealed the microstructure of the samples after the weld did not show any significant change with the base metal. Furthermore, this study scheme can be extended to thick non-ferrous, ferrous, and metal-based composite materials, too.

Optimization of friction stir welding parameters of dissimilar aluminium alloys 6061 and 5083 by using response surface methodology

2021 ◽  
pp. 095440622110058
Author(s):  
Sanjeev Verma ◽  
Vinod Kumar
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Tilt Angle ◽  
Feed Rate ◽  
Aluminium Alloys ◽  
Welded Joint ◽  
Welding Parameters ◽  
Friction Stir ◽  
Industrial Sectors ◽  
Tool Pin

Aluminium and its alloys are lightweight, corrosion-resistant, affordable and high-strength material and find wide applications in shipbuilding, automotive, constructions, aerospace and other industrial sectors. In applications like aerospace, marine and automotive industries, there is a need to join components made of different aluminium alloys, viz. AA6061 and AA5083. In this study friction stir welding (FSW) is used to join dissimilar plates made of AA6061-T6 and AA5083-O. The effect of varying tool pin profile, tool rotation speed, tool feed rate and tilt angle of the tool has been investigated on the tensile strength and percentage elongation of the welded joints. Box-Behkan design, with four input parameters and three levels of each parameter has been employed to decide the set of experimental runs. The regression models have been developed to investigate the influence of welding variables on the tensile strength and elongation of the welded joint. It is revealed that with the increase in welding parameters like tool rpm, tool feed rate and tilt angle of the tool, both the mechanical properties increase, reach a maximum level, followed by a decrease with further increase in the value of parameters. Amongst different types of tool pin profiles used, the FSW tool having straight cylindrical (SC) pin profile is found to yield the maximum strength and elongation of the welded joint for different combinations of welding parameters. Multiple response optimization indicates that the maximum UTS (135.83 MPa) and TE (4.35%) are obtained for the welded joint fabricated using FSW tool having SC pin profile, tilted at 1.11° and operating at tool speed and feed rate of 1568 rpm and 39.53 mm/min., respectively.

scholarly journals Effect of Stirring Pin Rotation Speed on Microstructure and Mechanical Properties of 2A14-T4 Alloy T-Joints Produced by Stationary Shoulder Friction Stir Welding

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1938
Author(s):  
Haifeng Yang ◽  
Hongyun Zhao ◽  
Xinxin Xu ◽  
Li Zhou ◽  
Huihui Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Rotation Speed ◽  
Weld Nugget ◽  
Al Alloy ◽  
Nugget Zone ◽  
T Joints ◽  
Friction Stir ◽  
Stationary Shoulder ◽  
Microstructure And Mechanical Properties

In this study, 2A14-T4 Al-alloy T-joints were prepared via stationary shoulder friction stir welding (SSFSW) technology where the stirring pin’s rotation speed was set as different values. In combination with the numerical simulation results, the macro-forming, microstructure, and mechanical properties of the joints under different welding conditions were analyzed. The results show that the thermal cycle curves in the SSFSW process are featured by a steep climb and slow decreasing variation trends. As the stirring pin’s rotation speed increased, the grooves on the weld surface became more obvious. The base and rib plates exhibit W- or N-shaped hardness distribution patterns. The hardness of the weld nugget zone (WNZ) was high but was lower than that of the base material. The second weld’s annealing effect contributed to the precipitation and coarsening of the precipitated phase in the first weld nugget zone (WNZ1). The hardness of the heat affect zone (HAZ) in the vicinity of the thermo-mechanically affected zone (TMAZ) dropped to the minimum. As the stirring pin's rotation speed increased, the tensile strengths of the base and rib plates first increased and then dropped. The base and rib plates exhibited ductile and brittle/ductile fracture patterns, respectively.

Effect of Friction Stir Welding Parameters on Thermal and Tensile Behavior of Aluminum Weldments Using Double Shoulder Tools

2012 ◽  
Vol 622-623 ◽  
pp. 323-329
Author(s):  
Ebtisam F. Abdel-Gwad ◽  
A. Shahenda ◽  
S. Soher
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Welding Process ◽  
Tensile Behavior ◽  
Frictional Heat ◽  
Welding Parameters ◽  
Friction Stir ◽  
Aluminum Base ◽  
Tool Pin ◽  
Strength And Ductility

Friction stir welding (FSW) process is a solid state welding process in which the material being welded does not melt or recast. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters and tool pin profile play major roles in deciding the weld quality. In this investigation, an attempt has been made to understand effects of process parameters include rotation speeds, welding speeds, and pin diameters on al.uminum weldment using double shoulder tools. Thermal and tensile behavior responses were examined. In this direction temperatures distribution across the friction stir aluminum weldment were measured, besides tensile strength and ductility were recorded and evaluated compared with both single shoulder and aluminum base metal.

scholarly journals Friction Stir Welding of AA2024-T3 plate – the influence of different pin types

2015 ◽  
Vol 6 (1) ◽  
pp. 51-55 ◽  
Author(s):  
D. Trimble ◽  
H. Mitrogiannopoulos ◽  
G. E. O'Donnell ◽  
S. McFadden
Keyword(s):  
Friction Stir Welding ◽  
Parent Material ◽  
Micro Hardness ◽  
Workpiece Material ◽  
Friction Stir ◽  
Hardness Tests ◽  
Weld Profile ◽  
Unaffected Parent ◽  
Line Defects ◽  
Tool Pin

Abstract. Some aluminium alloys are difficult to join using traditional fusion (melting and solidification) welding techniques. Friction Stir Welding (FSW) is a solid-state welding technique that can join two plates of material without melting the workpiece material. This proecess uses a rotating tool to create the joint and it can be applied to alumium alloys in particular. Macrostructure, microstructure and micro hardness of friction stir welded AA2024-T3 joints were studied. The influence of tool pin profile on the microstructure and hardness of these joints was examined. Square, triflute and tapered cylinder pins were used and results from each weldment are reported. Vickers micro hardness tests and grain size measurements were taken from the transverse plane of welded samples. Distinct zones in the macrostructure were evident. The zones were identified by transitions in the microstructure and hardness of weld samples. The zones identified across the sample were the the unaffected parent metal, the Heat Affected Zone (HAZ), the Thermo-Mechanicaly Affected Zone (TMAZ), and the Nugget Zone (NZ). Measured hardness values varied through each FSW zone. The hardness in each zone was below that of the parent material. The HAZ had the lowest hardness across the weld profile for each pin type tested. The cylindrical pin consistently produced tunnel and joint-line defects. Pin profiles with flat surface features and/or flutes produced consolidated joints with no defects.

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