Properties Of Friction Stir Welding Research Articles

Experimental and numerical studies of relationship between microstructures and mechanical properties in friction stir welding under water

Experimental and numerical studies of relationship between microstructures and mechanical properties in friction stir welding under water

Microstructures and mechanical properties of friction stir welded additively manufactured Scalmalloy®

The development of high-strength advanced additively manufactured (AM) aluminum alloys is driven by the need for weight reduction in complex-shaped structural applications. In this context, heat-treatable aluminum-scandium alloy, known commercially as Scalmalloy®, offers high strength and lightness, also at high temperatures, due to solution strengthening Al3(Sc, Zr) particles. A widespread diffusion of such AM alloy is also related to welding technologies that could preserve its engineered microstructure. This study investigates the microstructural and mechanical properties of butt friction stir welding (FSW) joints of LPBF Scalmalloy® plates under different welding settings. Joint performance was evaluated under quasi-static and cyclic loading conditions. Porosity in Scalmalloy® and welds was assessed using 3D X-ray computed tomography. An aging heat treatment assessed the extent of precipitation hardening in the FSW joints. Results show that metal stirring during FSW notably reduced the intrinsic porosity of Scalmalloy®, decreasing the equivalent pore diameter from about 200 μm to 60 μm in the welded joints. Under quasi-static loading, welded specimens failed at the interface between the thermo-mechanically affected and the stir zones on the advancing side. The aging heat treatment improved the mechanical strength of Scalmalloy® from approximately 400 to 480 MPa, albeit at the expense of ductility (elongation at fracture decreased from 16 to 4%). The higher heat input and stirring developed at a low welding speed reduced lazy S defects but limited the effectiveness of subsequent aging. In fatigue testing, welded joints consistently failed within the aged base material due to the intrinsic porosity of Scalmalloy®.

Effect of process parameters on weld geometry and mechanical properties in friction stir welding of AA2024 and AA7075 alloys

FSW joints are promising because they have a minimal heat input in welding and can limit the amount of intermetallic compound formation in dissimilar metals. Solid-state welding processes, particularly friction stir welding (FSW), are preferred for welding aluminium alloys due to their low heat input and ability to minimize intermetallic compound formation. This study conducted FSW trials on AA7075 and AA2024 alloys, each 4 mm thick. Parameters such as axial force, rotational speed, and traverse feed were adjusted while keeping other factors constant. The study analyzed weld geometry characteristics, including bead width and penetration depth. Angle distortions during FSW of thin plates in a butt joint were investigated. Additionally, the study examined the effects of FSW parameters on mechanical properties such as tensile strength and hardness immediately after welding. Microstructures of the welds were observed using optical microscopy (OM). The optimal mechanical properties are achieved at a rotational speed of 1000 rpm, a traverse feed of 30 mm/min, and an axial force of 10 kN. This optimal condition facilitates material flow around the pin at an ideal speed, ensuring adequate material filling and preventing tunnel formation. The stir zone's microstructure under these parameters exhibits a finely recrystallized structure with a significantly smaller grain size than the base material. Consequently, this enhances the joint's microhardness and tensile strength.

Investigation of The Weldability of PLA Plus Sheets with Different Infill Ratios by Friction Stir Welding

Although the joining processes of plastics are typically carried out through welding, adhesive bonding, or mechanical fastening elements, the production of complex and large parts often requires welding technology. In this study, the effect of part infill ratio (20%, 40%, 60%, 80%, and 100%) on the welding strength of 3D printed PLA Plus parts was evaluated through friction stir welding (FSW). Tensile tests and temperature measurements were carried out to examine the effects of friction stir welding process parameters (feed rate: 50 and 100 mm/min and rotational speed: 1000 and 1500 rpm) on the structure and mechanical properties of friction stir welding. Moreover, visual inspections were performed to detect defects in the weld zone. Compared to the PLA Plus samples given as reference according to the infill ratios, the highest welding strengths were obtained at 80%, 60% and 100% infill ratios (29.4 MPa, 17.47 MPa and 41.12 MPa and 112.38%, 97.48%, 87.04% efficiency, respectively). As a result, it was determined that at low infill ratios (20% and 40%), the weld quality was negatively affected, and a surface tunnel defect occurred in the weld zone. It has been determined that the weld quality in FSW is significantly affected by the temperature occurring during the process. The study has shown that parts printed at different infill ratios, especially on a 3D printer, can be combined with friction stir welding and that the efficiency of the welding process can be increased by optimizing the infill ratios.

Measurement of Mechanical Properties of Friction Stir Welding of Al–Li alloy under different environmental conditions

Measurement of Mechanical Properties of Friction Stir Welding of Al–Li alloy under different environmental conditions

Experimental Investigation of Mechanical Properties in Friction Stir Welding for Butt Joints with Different Thicknesses Using Response Surface Methodology

Experimental Investigation of Mechanical Properties in Friction Stir Welding for Butt Joints with Different Thicknesses Using Response Surface Methodology

Retracted: Analysis of Temperature Distribution and Mechanical Properties of Friction Stir Welding of Al-Cu Joints Using Hardened H13 Steel Tools

Retracted: Analysis of Temperature Distribution and Mechanical Properties of Friction Stir Welding of Al-Cu Joints Using Hardened H13 Steel Tools

Effect of in-situ ZrB2 nanoparticles on microstructure and mechanical properties of friction stir welding joints in 7N01 matrix composites

In this paper, in-situ nanoparticles ZrB2 were introduced to improve the mechanical properties of Friction Stir Welding (FSW) joints in 7N01 matrix composites. The recrystallization driving force was increased induced by ZrB2 particles. Modified by ZrB2 nanoparticles, the grains in the SZ (stir zone) were refined from 4.8 μm (7N01) to 3.7 μm (ZrB2/7N01), and the recrystallization proportion was increased from 75.1% (7N01) to 85.4% (ZrB2/7N01). Compared with the 7N01 matrix, the ultimate tensile strength (UTS) of friction stir welding joints in ZrB2/7N01 composites was enhanced from 283.3 to 395.6 MPa, the yield strength (YS) was enhanced from 250.8 to 361.4 MPa, elongation was enhanced from 12.7% to 16.2%. The strengthening effect was mainly achieved through the Orowan mechanism. The MgZn2 precipitates grew up under the influence of heat input, the inhibiting effect of precipitates on dislocations movement was weakened. Nanosized ZrB2 particles with superior coarsening resistance can still maintain its morphology and size at high temperature, playing a good strengthening role during the FSW.

Hybrid heuristic methods exercising to optimize the friction stir welding process parameters for improving the prepared butt joints mechanical properties

PurposeThe weld joint mechanical properties of friction stir welding (FSW) are majorly reliant on different input parameters of the FSW machine. The study and optmization of these parameters is uttermost requirement and aim of this study to increase the suitability of FSW in different manufacturing industries. Hence, the input parameters are optimized through different soft computing methods to increase the considered objective in this study.Design/methodology/approachIn this research, ultimate tensile strength (UTS), yield strength (YS) and elongation (EL) of FSW prepared butt joints of AA6061 and AA5083 Aluminium alloys materials are investigated as per American Society for Testing and Materials (ASTM E8-M04) standard. The FSW joints were prepared by changing the three input process parameters. To develop experimental run order design matrix, rotatable central composite design strategy was used. Furthermore, genetic algorithm (GA) in combination (Hybrid) with response surface methodology (RSM), artificial neural network (ANN), i.e. RSM-GA, ANN-GA, is exercised to optimize the considered process parameters.FindingsThe maximum value of UTS, YS and EL of test specimens on universal testing machine was measured as 264 MPa, 204 MPa and 14.41%, respectively. The most optimized results (UTS = 269.544 MPa, YS = 211.121 MPa and EL = 17.127%) are obtained with ANN-GA for the considered objectives.Originality/valueThe optimization of input parameters to increase the output objective values using hybrid soft computing techniques is unique in this research paper. The outcomes of this study will help the FSW using manufacturing industries to choose the best optimized parameters set for FSW prepared butt joint with improved mechanical properties.

The effect of pin thread on material flow and mechanical properties in friction stir welding of AA6068 and pure copper

This study investigated the effects of friction stir welding thread on the quality of dissimilar joints between AA6068 aluminum alloy and copper. The developed computational fluid dynamic (CFD) method was employed to simulate the tool's heat generation and thermo-mechanical action. The materials flow, microstructure, mechanical properties, and hardness of joints were assessed. The results indicated that the threaded pin increased heat generation during welding. The maximum temperature recorded on the aluminum side was 780 K for the cylindrical joint and 820 K for the threaded pin joint. The size of the stir zone in the threaded pin joint was bigger than the cylindrical pin. On the other hand, mechanical interlocking between AA6068 aluminum alloy and copper increased in the threaded pin joint. The material's velocity and strain rate increased by the higher stirring action of the threaded tool. Higher strain rate and materials velocity decreased microstructure size in the stir zone. The experimental result shows that the ultimate tensile strength of the cylindrical pin joint was 272 MPa, and the threaded pin joint was 345 MPa. The average microhardness of the cylindrical pin joint was near 104 H V, and for the threaded pin was 109 H V. The results show that the ultimate tensile strength and hardness of threaded pin joint increases by 25% and 5% in comparing cylindrical pin joint.

Through-thickness heterogeneity in creep properties of friction stir welding 7B50-T7451 aluminum alloy thick plate joint: Experiments and modeling

Through-thickness heterogeneity in creep properties of 7B50-T7451 aluminum alloy Friction Stir Welding (FSW) joints was investigated. Creep tests for three slices of the FSW joint were conducted at the temperature of 150–200 °C and applied stress of 60–225 MPa. The theta projection method was used to predict creep curves and minimum creep rate. The results show that the minimum creep rate increases and creep rupture life decreases with the increase of creep temperature and applied stress. Creep properties of the FSW joint deteriorate along the thickness direction from the top to the bottom. The threshold stress of all three slices of the FSW joint decreases with the increase of creep temperature and even disappears at 200 °C for the bottom slice. Creep activation energy approaches the activation energy of the lattice self-diffusion of aluminum. The value of true stress exponent for different slices is approximately equal to three. The predominant creep mechanism of the FSW joint is dislocation viscous glide by lattice self-diffusion. What is more, a constitutive model is established based on the theta method to accurately describe creep behavior of different slices of the FSW joint.

Tool pin profiles effect on mechanical properties of friction stir welding of dissimilar aluminium alloys

Aluminum alloys are now widely used in a many of the engineering applications because of due to their light weight and exceptional characteristics. In many precision sectors such as automobile, railway, aerospace, and marine structures joining is considered one of the most complicated phenomena because rigid tolerances are necessary throughout distinct product assembly. Friction stir welding (FSW) of various grades of aluminium alloys has attracted significant industrial and scientific attention due to its ability to transform into a high-quality joint product. Fabricating such alloys with traditional fusion welding is a difficult process because of many metallurgical problems. In the present experimental work, the effect of different pin profiles tools on friction stir welding of AA-6061 T6 and AA-2014 T4 has been investigated. Friction stir welding has been performed using different pin profiles tools cylindrical, square and tapered and keeping the rotational speed and feed rate constant. This experimental investigation shows that by using square profile tool for friction stir welding improves the mechanical properties of the joint. It has also been observed that hardness of the weld is greater for square pin profile. Also the microstructure of the samples was observed.

The Effect of Tool Rotation on Structure and Mechanical Properties in Friction Stir Welding Of Aluminum AA5052

Abstract: Welding of aluminum alloy materials is often used in the industrial world, including those engaged in shipping, aircraft, and others. The welding method used to bind aluminum materials is Friction Stir Welding (FSW). Friction Stir Welding (FSW) is a simple welding method, namely by utilizing the heat energy generated from the friction of the shoulder tool with the material being welded. This study aimed to determine the effect of tool rotation on the physical and mechanical properties of Friction Stir Welding of Aluminum AA5052. The material used in this study was aluminum with the series AA5052 as the primary material. The friction stir welding process was carried out using CnC milling with parameters of the tool rotation speed of 1000, 1200, and 1500 rpm and a feed rate of 25 mm/minute. Physical analysis was carried out using macro photo observations with a USB Digital Microscope and microstructural observations with optical metallography. Mechanical observations were carried out using tensile testing and hardness testing. The microstructure in the weld nugget area shows good results with fine and dense grains that occur due to the dynamic recrystallization process. The highest tensile strength is 102.49 MPa in the 1000 rpm parameter. This is due to the material mixing process and good heat transfer.

Understanding the Material Flow Mechanisms—Microstructure Evolution—Defect Formation Relationships and Effects on Mechanical Properties in Friction Stir Welding of Dissimilar Aluminum Alloys

Understanding the Material Flow Mechanisms—Microstructure Evolution—Defect Formation Relationships and Effects on Mechanical Properties in Friction Stir Welding of Dissimilar Aluminum Alloys

Modelling, Temperature Analysis, and Mechanical Properties of Friction Stir Welding of Al-Cu Joints with Hardened OHNS Steel Tools

Friction stir welding (FSW) is a nearly modern welding method with vital advantages over the conventional welding process, such as lower distortion, enhanced mechanical properties, and eco- friendly. In FSW, the joint characteristics mainly depend on heat development during the joining process due to its solid-state joining method. The basic principles of thermomechanical methods during FSW are unknown since it is a new metal joining method. In this investigation, the 2D and 3D models of the tools with different pin forms were designed using SOLIDWORKS. The ANSYS software was used to investigate the temperature distributions near the weld zones. The fixture was designed and made according to the machine conditions. The base plates used were AA6101 and C11000; the tool material used was the Hardened OHNS steel tool with square and circular pin form. The temperature values were measured in each trial while joining of Al-Cu base plates along the weld line. The results reveal that in the joint area, a trial with high temperature leads to high ultimate tensile strength (UTS) and Charpy impact strength (CIS). Made at tool rotation speed 1200 rpm and feed velocity 20 mm/min of Hardened OHNS steel tool with circular pin form. The obtained UTS value at joints was less than that of Al and Cu base plates. The microhardness value detected at the joint area was higher than the Al and Cu base plates, providing high strength, and irregularly dispersed.

The effect of microstructure on corrosion behaviour and mechanical properties of friction stir welds of AA2519 and AA2219 Al-alloys

The highly weldable AA2219 Al-Cu alloy has been amended as AA2519 Al-Alloy to increase its ballistic resistance. Despite the fact that the mechanical properties of friction stir(FS) welds are improved, corrosion resistance is affected as a result of the diverse microstructural changes which occurs in different zones in the course of welding.Present work is planned to compare and correlate the effect of microstructure on mechanical and corrosion behaviour of AA2219 and AA2519 FS welds. Results of the work shown better corrosion resistance and mechanical properties of AA2519 welds when compared to that of AA2219 welds. The presence of strengthening precipitates Al 2 CuMg, Al 3 Zr and Al 3 Ti provides insulation path for galvanic cell formation between the Al 2 Cu and Al matrix, may be the reason for improved corrosion resistance in AA2519 Al-alloys and it’s welds. Overall it was found that better combination of strength and corrosion resistance was obtained for AA2519 Al-alloy welds. • For the first time a systematic comparison is made between the Microstructure, Mechanical properties and corrosion behaviour of AA2219 and AA2519 alloy friction stir welds. • Effect of precipitates like Al 2 CuMg, Al 3 Zr and Al 3 Ti on mechanical and corrosion properties of AA2519 and AA2219 alloy friction stir welds was studied. • Observed tensile properties and corrosion behaviour was correlated with the microstructure of AA2519 and AA2219 alloy friction stir welds. • Present study is proved that a good combination of tensile strength and corrosion resistance can be achieved in Friction stir welds of AA2519.

Effect of microstructure inhomogeneity on creep behavior of friction stir welding 7B50-T7451 aluminum alloy thick plate joint

Microstructure inhomogeneity and through-thickness creep properties of friction stir welding (FSW) 7B50-T7451 aluminum alloy thick plate joint were investigated. The results show that creep properties of the FSW joint deteriorate along the thickness direction from the top to the bottom. Both the grain size and fraction of the low-angle grain boundaries (LAGBs) in the weld nugget zone (WNZ) decrease from the top to bottom. A larger volume of precipitate free zone (PFZ) and coarser precipitates in the bottom slice reduce creep resistance compared with the top. The precipitates in the heat-affected zone (HAZ) exhibit continuous coarsening with the increase of creep temperature, inducing the decrease of threshold stress. The dominant creep mechanism transforms from dislocation creep in the HAZ to grain boundary sliding (GBS) in the WNZ when creep temperature increases. The fracture mode also changes from transgranular to intergranular fracture.

Analysis of Temperature Distribution and Mechanical Properties of Friction Stir Welding of Al-Cu Joints Using Hardened H13 Steel Tools

Friction Stir Welding (FSW) is a superior metal joining technique for joining similar and dissimilar metals. The various materials acceptable for the FSW techniques were magnesium alloys, mild steel, stainless steel, copper alloys, titanium alloys, aluminium alloys, etc. In this method, the frictional heat generated by the tool on metal workpieces was used for joining, and the workpieces were joined below the upper critical temperature. The substantial benefit of this technique is that it is capable of welding unweldable alloys by the conventional fusion welding method. The welding tool was rotated, traversed, and penetrated into the joint between two base plates. A suitable tool design with appropriate process parameters will result in high-quality welding on workpieces. In these experiments, the tools were designed with different pin profiles. The welding tools required for FSW are designed using SOLIDWORKS, and temperature distributions across the weld regions were analyzed using Ansys software. The fixture needed for FSW is fabricated according to machine requirements. The tool material used was hardened H13 steel, and the base plates were aluminium alloy 6101 and copper alloy C11000. The temperature distributions are noted in each trial during FSW of Al-Cu joints along the weld line region. Due to maximum temperature at weld joints, high ultimate tensile strength and impact strength were obtained at 1200 rpm tool rotational speed and 20 mm/min feed rate with the square pin profile of a hardened H13 steel tool. The obtained ultimate tensile stress (UTS) at joints was less than that of the base plates Al and Cu. The microhardness value was higher at the nugget zone than at the base plates, giving high strength at the joint area and unevenly distributed.

A review of effect on metallurgical properties of friction stir welding using high entropy alloy

The work summarizes the review of use of High Entropy Alloy in the Friction Stir Welding. When High Entropy Alloy is utilized in the Friction Stir Welding the resultant mechanical, metallurgical as well as corrosive properties show the influence of HEA base material properties. The Process used to obtain HEA provides base properties affecting the microstructural impact due to heat generation in FSW. Taking into account HEA, FSW too improve the welding properties of the material. The grain size was affected by heat generation and pressure of rotational as well as transverse speed, and could be differentiated in different zones (SZ, HAZ, and TMAZ) and sides (advancing, retreating, top, and bottom). Results of misorentation, HABs, and LABs were influences by the type of recrystallization. GGAE are associated to HABs and SFE to heating phenomenon, so overall it is HEA reaction to the heat generation in different areas and its effects seen in recrystallization of grains.

Mechanical Properties Enhancement of Dissimilar AA6061-T6 and AA7075-T651 Friction Stir Welds Coupled with Deep Rolling Process.

The main purpose of this research was to enhance the mechanical properties of friction stir welds (FSW) in the dissimilar aluminum alloys 6061-T6 and 7075-T651. The welded workpiece has tensile residual stress due to the influence of the thermal conductivity of dissimilar materials, resulting in crack initiation and less fatigue strength. The experiment started from the FSW process using the 2k full factorial with the response surface methodology (RSM) and central composite design (CCD) to investigate three factors. The experiment found that the optimal rotation speed and feed rate values were 979 and 65 mm/min, respectively. Then, the post-weld heat treatment process (PWHT) was applied. Following this, the 2k full factorial was used to investigate four factors involved in the deep rolling process (DR). The experiment found that the optimal deep rolling pressure and deep rolling offset values were 300 bar and 0.2 mm, respectively. Moreover, mechanical property testing was performed with a sequence of four design types of workpieces: FSW, FSW-PWHT, FSW-DR, and FSW-PWHT-DR. It was found that the FSW-PWHT-DR workpiece had an increase in tensile strength of up to 26.29% and increase in fatigue life of up to 129.47% when compared with the FSW workpieces, as well as a maximum compressive residual stress of −414 MPa.