scholarly journals Analysis of the Oscillation Behavior of Hybrid Aluminum/Steel Joints Realized by Ultrasound Enhanced Friction Stir Welding

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1079
Author(s):  
Marco Thomä ◽  
Andreas Gester ◽  
Guntram Wagner ◽  
Marco Fritzsche
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Fusion Welding ◽  
Laser Vibrometer ◽  
Particle Volume ◽  
Dissimilar Joints ◽  
Additional Energy ◽  
Power Ultrasound ◽  
Friction Stir ◽  
Ultrasound Enhancement

Friction stir welding (FSW) is an innovative solid-state joining process, which is suitable for joining dissimilar materials with strongly differing physical and chemical properties such as aluminum and steel. Where other joining methods such as fusion welding struggle to achieve appropriate joint strengths due to the excessive formation of brittle aluminum-rich intermetallic phases (IMP), FSW joints of aluminum and steel only show small layers of IMP, thus, sufficient tensile strengths in proximity to the maximum tensile strength of the weaker aluminum base material can be reached. With the aim to optimize the mechanical and microstructural properties of such dissimilar joints for widening the field for possible industrial applications, several hybrid friction stir welding methods have been developed which include an additional energy input, whereas the ultrasound enhancement (USE-FSW) is one of the most promising. The current work was carried out on AA6061/DC04 joints which were successfully friction stir welded with and without ultrasound support, in respect to the influence of varying the ultrasound transmission side. The functionality of the USE-FSW setup could be verified by multi point laser vibrometer measurements. Additionally, a higher proportion of transversal oscillation for the transmission of power ultrasound into aluminum could be detected using a scanning vibrometer. In comparison to the conventionally friction stir welded joints the ultrasound enhancement led to an avoidance of weld defects and an increase of the steel particle volume in the stir zone. The joint produced with power ultrasound transmission via aluminum resulted in a more uniform interface.

The Influence of Ultrasound Enhancement during Friction Stir Welding of Aluminum to Steel

2018 ◽  
Vol 767 ◽  
pp. 351-359 ◽  
Author(s):  
Marco Thomä ◽  
Guntram Wagner ◽  
Benjamin Straß ◽  
Bernd Wolter ◽  
Sigrid Benfer ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Dissimilar Materials ◽  
Dissimilar Joints ◽  
Power Ultrasound ◽  
Friction Stir ◽  
Wide Range ◽  
Steel Joints ◽  
Welding Processes ◽  
Ultrasound Enhancement

The innovative joining process of friction stir welding (FSW) offers a wide range of advantages for welding similar as well as dissimilar materials. Even for the field of poorly weldable material combinations like aluminum to steel with their strongly differing physical properties the method of FSW proved its capability for realizing dissimilar joints with tensile strengths up to more than 80 % of the aluminum base material. Trying to improve this value and other properties of the joints several approaches for hybrid friction stir welding processes were tested in the scientific community, whereas the ultrasound enhancement of FSW (USE-FSW) looked as one of the most promising reaching good results. To gain a deeper knowledge of the influence of the ultrasound on the friction stir welds different investigations were carried out in this paper. Therefore the method of USE-FSW was applied on two dissimilar aluminum/steel-joints with varying carbon content of the steel in this work. The material combinations AA6061/SAE1006 and AA6061/SAE1045 were welded successfully with and without additional power ultrasound. Afterwards a comparison between FSW-and USE-FSW-joints was carried out regarding the microstructure of the nugget and interface (IF) by light-microscopy as well as scanning electron microscopy. Furthermore the mechanical properties were characterized in a first step.

scholarly journals Dissimilar Friction Stir Butt Welding of Aluminum and Copper with Cross-Section Adjustment for Current-Carrying Components

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 661 ◽  
Author(s):  
Nima Eslami ◽  
Alexander Harms ◽  
Johann Deringer ◽  
Andreas Fricke ◽  
Stefan Böhm
Keyword(s):  
Friction Stir Welding ◽  
Cross Section ◽  
Tensile Force ◽  
Base Material ◽  
Metallographic Analysis ◽  
Dissimilar Joints ◽  
Butt Welding ◽  
Friction Stir ◽  
Aluminum Base ◽  
Electrical Conductors

Manufacturing dissimilar joints of aluminum and copper is a challenging task. However, friction stir welding (FSW) was found to be a suitable technique to produce aluminum–copper joints. Due to different electrical conductivities between aluminum and copper, an adjustment of the cross-section is required to realize electrical conductors free of resistive losses. Taking this into account, this paper presents initial results on the mechanical and electrical properties of friction stir butt welded aluminum and copper blanks having thicknesses of 4.7 mm and 3 mm, respectively. Three different approaches were investigated with the aim to produce sound welds with properties similar to those of the used base materials. Friction stir welding has been conducted at a welding speed of 450 mm/min. Subsequently, the welded specimens were subjected to metallographic analysis, tensile testing, and measurements of the electrical conductivity. The ultimate tensile force of the best joints was about 10 kN, which corresponds to joint efficiencies of approximately 72% of the aluminum base material. The analysis of electrical joint properties led to very promising results, so that the potential of FSW of Al–Cu butt joints with sheets having different thicknesses could be confirmed by the investigations carried out.

scholarly journals WELDABILITY AND MECHANICAL PROPERTIES OF DISSIMILAR AL-MGSI TO PURE ALUMINIUM AND AL-MG USING FRICTION STIR WELDING PROCESS

2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Nor Fazilah Mohd Selamat ◽  
Amir Hossein Baghdadi ◽  
Zainuddin Sajuri ◽  
Amir Hossein Kokabi
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloys ◽  
Welding Process ◽  
Fusion Welding ◽  
Welding Parameter ◽  
Pure Aluminium ◽  
Base Metals ◽  
Dissimilar Joints ◽  
Friction Stir ◽  
Solid State Joining

Friction stir welding (FSW) is a gateway for the implementation of a solid state joining method between two lightweight materials especially aluminium alloys. Dissimilar joints of aluminium alloys have an issue to be weld using the conventional fusion welding. In the present work, two types of dissimilar joints of aluminium alloys were welded as dissimilar butt joints using the FSW method. 5mm thick base metals, consist of AA1100, AA5083 and AA6061, were butt welded to dissimilar joints of AA6061-AA1100 and AA6061-AA5083. Similar welding parameter was used for both of the joints, in which 100 mm/min and 1000 rpm for transverse and rotation speed, respectively. Joints were successful with defect-free internally and externally. However, different flow patterns were observed in the stirred zone due to the different materials flow during the FSW process. The ultimate tensile strength of AA6061-AA1100 and AA6061-AA5083 are 93MPA and 113MPa. Thereby, the joint efficiency of AA6061-AA1100 and AA6061-AA5083 were 80% and 97% compared to AA6061 base metal, respectively.

Influence of plunge depth during friction stir welding of aluminum pipes

2020 ◽  
pp. 095440542094975
Author(s):  
Md Perwej Iqbal ◽  
Ranjan Kumar Vishwakarma ◽  
Surjya K Pal ◽  
Parthasarathi Mandal
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Fusion Welding ◽  
Influence Of Process Parameters ◽  
Friction Stir ◽  
Lack Of Fusion ◽  
Slag Inclusions ◽  
Key Issues ◽  
Physical Responses ◽  
Root Crack

This study focuses on the application of friction stir welding (FSW) process for joining of pipes. It addresses key issues associated with fusion welding techniques, such as lack of fusion, over penetration, slag inclusions, root crack, undercut root gap, and thermal distortion. The influence of process parameters on the physical properties during FSW of aluminum pipes has been studied, which allows selecting an optimum combination of parameters for achieving superior welds. Physical responses such as variation in axial force, torque, temperature, and power have been analyzed. Tensile test of the joints fabricated shows a maximum of ∼90% joint strength efficiency with respect to the base material. The peak temperature or heat input is found to be increasing during FSW, which creates a larger grain size in the stir zone of the joints, resulting in the higher hardness of the joints.

scholarly journals Influence of Mx-Trivex, A-Skew, Three Flat Threaded and Concave Shouldered Mx-Triflute Tool Pin Profiles on Tensile Properties and Fractural Behaviour of Aa 6082-T6 Weldments During Friction Stir Welding

2020 ◽  
Vol 9 (4) ◽  
pp. 1376-1384
Keyword(s):  
Friction Stir Welding ◽  
Tensile Test ◽  
Weld Zone ◽  
Base Material ◽  
Traverse Speed ◽  
Friction Stir ◽  
Tool Pin ◽  
Solid State Joining ◽  
Joining Process ◽  
Brass Wire

Friction Stir Welding (FSW) is a topical and propitious solid-state joining process producing economical and strengthened joints of age-hardened and heat-treatable Aluminium Alloy AA 6082-T6. Mechanical and fractural behaviour of weldments were investigated in order to find crack initiation and necking on the weld zone thereby perceiving the complete behaviour of fracture occurred near the weld zone. Weldments are fabricated by employing four tool pin profiles namely MX-TRIVEX, A-SKEW, Three flat threaded and Concave shouldered MX-TRIFLUTE tools at various rotational speeds 1000 rpm, 1200 rpm and 1400 rpm at single traverse speed 25 mm/min. EXCETEX-EX-40 CNC wire cut EDM with 0.25 mm brass wire diameter has been employed to perform the extraction of tensile test specimens from the weldments according to ASTM E8M-04 standard. Tensile test was performed on elctromechanically servo controlled TUE-C-200 (UTM machine) according to ASTM B557-16 standards Maximum Ultimate Tensile Strength (UTS) of 172.33 MPa (55.5% of base material) and 0.2% Yield Stress (YS) of 134.10 MPa (51.5% of base material) were obtained by using A-SKEW at 1400 rpm, 25 mm/min and maximum % Elongation (%El) of 11.33 (113.3% of base material) was obtained at MX-TRIVEX at 1000 rpm, 25 mm/min. Minimum UTS of 131.16 MPa (42.30% of base material) and 0.2% YS of 105.207 MPa (40.46% of base material )were obtained by using Concave shouldered MX-TRIFLUTE at 1400 rpm, 25 mm/min. Minimum % El of 5.42 ( 54.2% of base material) was obtained by using A-SKEW at 1000 rpm, 25 mm/min.

scholarly journals The Effects of In-Process Cooling during Friction Stir Welding of 7475 Aluminium Alloy

2021 ◽  
Vol 50 (9) ◽  
pp. 2743-2754
Author(s):  
Ashish Jacob ◽  
Sachin Maheshwari ◽  
Arshad Noor Siddiquee ◽  
Abdulrahman Al-Ahmari ◽  
Mustufa Haider Abidi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Welded Joints ◽  
Positive Impact ◽  
Welding Process ◽  
Fusion Welding ◽  
Friction Stir ◽  
Cooling Conditions ◽  
Zero Degree ◽  
Welding Technique

Certain age hardenable alloys such as AA7475 cannot be joined with perfection using fusion welding techniques. This requires non-conventional welding technique such as friction stir welding process to join these ‘difficult to weld’ alloys. In this study, three different cooling conditions i.e. cryogenic, sub-zero, and zero-degree Celsius temperature conditions have been analyzed to understand its impact on the welding process. In-process cooling was found to behave effectively and also enhanced the mechanical properties of the welded joints. A stable microstructure was clearly seen in the images observed under the metallurgical microscope. The weld efficiencies were found to be good in each of the samples which are indicative of a strong metallic joint. The effective cooling conditions employed had an overall positive impact on the joint.

scholarly journals Design and Fabrication of Friction Stir Welding End-Effector for an ABB IRB1410 Robot

2016 ◽  
Vol 5 (2) ◽  
pp. 98
Author(s):  
Santosh Vanama
Keyword(s):  
Friction Stir Welding ◽  
High Strength ◽  
Fusion Welding ◽  
Fusion Temperature ◽  
End Effector ◽  
Friction Stir ◽  
Aluminum Sheets ◽  
Operation Pressure ◽  
Welding Processes ◽  
Tool Rotation

<p>The paper propose modelling and fabrication of friction stir welding end-effector for ABB IRB1410 robot. A dynamically developing version of pressure welding processes, join material without reaching the fusion temperature called friction stir welding. As friction stir welding occurs in solid state, no solidification structures are created thereby eliminating the brittle and eutectic phase’s common to fusion welding of high strength aluminium alloys. In this paper, Friction stir welding is applied to aluminum sheets of 2 mm thickness. A prototype setup is developed to monitor the evolution of main forces and tool temperature during the operation. Pressure of a gripper plays a major role for tool rotation and developing torque.  Fabrication of the tool has done. Force calculations are done by placing the sensors on the outer surface of gripper. Methods of evaluating weld quality are surveyed as well.</p>

Superplastic Behavior and Microstructure of Titanium (Ti-6Al-4V) Friction Stir Welds Made under a Variety of Processing Conditions

2010 ◽  
Vol 433 ◽  
pp. 169-176 ◽  
Author(s):  
Paul Edwards ◽  
Mamidala Ramulu ◽  
Daniel G. Sanders
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Superplastic Forming ◽  
Spindle Speed ◽  
Processing Conditions ◽  
Superplastic Behavior ◽  
Friction Stir ◽  
Fine Grained ◽  
Weld Parameters

Friction Stir Welding of Ti-6Al-4V was performed on 5 mm thickness plate in order to assess the affect of welding conditions on the resulting microstructure and superplastic forming behavior of the joints. A variety of welding conditions were tested and all welds were subsequently Superplastically formed. It was found that the weld parameters do influence the microstructure and degree of superplastic performance of the joints. Spindle speed was found to have the most dominant affect on the resulting microstructure and superplastic forming behavior. Low spindle speed welds lead to fine grained microstructures and highly superplastic welds, relative to the base material, while high spindle speed welds larger grained microstructures and less superplastic welds.

Multiaxial Mechanical Strength of AA-2024-T3 Aluminium Alloy Sheets Joined by Friction Stir Welding Processes

2009 ◽  
Vol 83-86 ◽  
pp. 1243-1250 ◽  
Author(s):  
R.L.L.P. Cerveira ◽  
G. F. Batalha
Keyword(s):  
Friction Stir Welding ◽  
Base Material ◽  
Short Review ◽  
Multiaxial Loading ◽  
Angle Variation ◽  
Friction Stir ◽  
Aa 2024 ◽  
Aeronautical Industry ◽  
Welding Processes ◽  
Joining Process

The aim is to analyze a junction produced by a Friction Stir Welding (FSW) joining process under multiaxial loading, employing a modified Arcan test that allows an angle variation of the loading in order to evaluate the failure of the FSW weldment as compared to the base material. A short review of the earlier studies and relevant theories about the FSW processes and fracture modes I and II under multiaxial loading are presented and were experimentally evaluated for an AA2024-T3 aluminum alloy sheets (t = 1.6 mm) processed by FSW. The results obtained can serve as a basis to compare the junctions made using FSW and conventional joint methods such as rivets (very common practice in the aeronautical industry).

Friction Stir Welding of Aluminum 6061-T6 and Multi-Purpose Copper 11000 Alloy

2017 ◽  
Author(s):  
Lewis N. Payton
Keyword(s):  
Friction Stir Welding ◽  
Copper Alloy ◽  
Tangential Velocity ◽  
Nuclear Industry ◽  
Fusion Welding ◽  
Alternative Methods ◽  
Friction Stir Weld ◽  
Tool Geometry ◽  
Work Piece ◽  
Friction Stir

Friction Stir Welding (FSW) is a solid-state joining process invented by The Welding Institute (TWI, United Kingdom) in 1991 in partnership with the National Aeronautics Space Agency. The process is emerging as one of the preferred alternative methods to permanently join materials that are difficult to join with traditional fusion methods (e.g., MIG, TIG, etc.). The welding of various copper alloys to various aluminum alloys is of great interest to the nuclear industry and the electrical distribution industry. The very different melting points of these two alloys preclude traditional fusion welding. Since the pin tool is simultaneously rotating and traversing through the work piece, flow around the tool is asymmetrical. This has led to designating one side of the tool as advancing and the opposite side as retreating. On the advancing side of the weld, the tool has a tangential velocity in the same direction as the weld is being created. The retreating side of the weld tool is the opposite. It can be can expected that asymmetric heating and deformation will occur in the weld due to this advancing/retreating nature of the FSW pin tool. Although previous studies have been performed that have observed this asymmetric behavior in both similar and dissimilar materials, the resulting welds have been of a poor quality. Large statistical experiments were conducted locally to study the effects of tool geometry, process parameters, and material composition have upon the friction stir butt welding of aluminum alloy 6061-T6 to copper alloy 11000 using a modern conventional 3-axis CNC vertical mill. The research seeks to determine (1) which direction a dissimilar metal friction stir weld between aluminum and copper should be executed, (2) the optimal shoulder diameter to be used when friction stir welding aluminum and copper on a CNC mill, and (3) the addition of a third material to act as an aide. The extensive statistical interactions between these parameters is also documented. A weld schedule was developed that resulted in an ultimate tensile strength (UTS) surpassing (greater than 90% of the weaker, more ductile copper alloy UTS strength) what has been documented in the current literature despite the machine limitations of the CNC vertical mill. Proper optimization of the welding schedule developed may approach 100 percent of the basic copper 11000 properties across the welded zone into the aluminum 6061-T6 alloy.

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