Weldability and mechanical properties of dissimilar aluminum-copper lap joints made by friction stir welding (original) (raw)
Related papers
Materials Today: Proceedings, 2019
This paper describes the feasibility of dissimilar friction stir welding (DFSW) of two different aluminum alloys; AA6101-T6 and AA6351-T6 of 6 mm plate thickness. The influence of process parameters like tool rotational speed, welding speed and axially downward force on the tensile and bending behavior of the welded plates has been studied. Weld joints were produced using EN32 tool steel with a cylindrical pin tool having 6 mm and 18 mm diameter of pin and shoulder respectively.For all the FSW joints, a constant welding speed 60mm/min was maintained andtool rotational speeds vary as of 900rpm, 1100rpm, 1300rpm and 1500 rpm respectively. From X-ray radiographs, it has been observed that joints welded at theselected process parameters gave good quality and no defects.XRD analyses were done to find out thepresence of mixing intermetallic compound in the FSWjoints. Transverse tensile test (as per ASTM E8 M) were performed to study the tensile strength of DFSW joints. The bending behaviors of weld joints have been conducted by three point bend test method experimentally using Universal Testing Machine.It is observed that good correlation exists between these two mechanical properties and rotational speeds. The defect free FSW butt joint produced at rotational speed 1300rpm gives the better mechanical propertiescompared to other joints.The ultimate tensile strength obtained at 1300rpm rotational speed is very close to the tensile strength of the base metals.
Friction Stir Welding of Dissimilar materials between AA6101 Aluminium and pure Copper
There are many applications where dissimilar Aluminium and Copper weldments are used. In present work Friction Stir Welding of AA6101 Aluminium and pure Copper plates of 5mm thickness in butt joint configuration is done. Friction stir welding is done at 700 rpm and at 11mm/min tool traverse speed with cylindrical H13 material tool. For this vertical machining center is used. Joint shows onion ring structure in stir zone. Cavity like defect are seen at the surface of joint. Tensile testing of joint is done using computerized UTM.
PERFORMANCE ANALYSIS OF FRICTION STIR WELDING ON ALUMINIUM AA7075 AND AA2024 ALLOY MATERIAL
Friction stir welding was invented at Welding institute, United Kingdom in the year 1991 and has ever since been proved to be one of the best solid state joining methods for materials such as aluminium and magnesium. Some of the aluminium alloys which are not weld able (Al-Cu, Al-Zn-Mg alloy) by fusion welding techniques, which produce defects and reduce the mechanical properties on the weld nugget could be welded using friction stir welding (FSW) successfully with excellent joint efficiencies. However effect of the process parameters on the properties of weld have not been investigated fully. In this study friction stir welding of aluminium alloys is selected for investigation. The welding process are to be conducted on varying the welding process parameters such as Tool rotation speed (RPM), Welding speed (mm/min), Downward force (KN) and Tool pin profile. The properties such as defects, microstructure, hardness, tensile and bend behaviour on welded plates are to be studied and compared with the base metal. Based on the results the process parameters are to be optimized.
Materials & Design, 2015
Dissimilar friction stir welding (FSW) of heat (AA 6082-T6) and non-heat (AA 5754-H22) treatable aluminium alloys, in lap joint configuration, was performed in this work. The base material plates were 1 mm thick. Welds were performed combining different plates positioning, relative to the tool shoulder, in order to assess the influence of base materials properties on welds strength. Three different tools were tested, one cylindrical and two conical, with different taper angles. Welds strength was characterized by performing transverse and tensile-shear tests. Strain data acquisition by Digital Image Correlation (DIC) was used to determine local weld properties. The results obtained enabled to conclude that the dissimilar welds strength is strongly dependent on the presence of the well-known hooking defect and that the hooking characteristics are strongly conditioned by base materials properties/positioning. By placing the AA 6082-T6 alloy, as top plate, in contact with the tool shoulder, superior weld properties are achieved independently of the tool geometry. It is also concluded that the use of unthreaded conical pin tools, with a low shoulder/pin diameter relation, is the most suitable solution for the production of welds with similar strengths for advancing and retreating sides.
Friction Stir Welding of Similar and Dissimilar Aluminium Alloys for Automotive Applications
Due to environmental issues, the efforts for light weighting in automobile design and manufacturing have become the main focus for automotive players to reduce fuel consumption and CO2 emission through intensive use of aluminium alloys. However, since aluminium alloys are known to be difficult to weld, joining of similar and dissimilar aluminium alloys in automotive are crucial to be solved. In this study, the friction stir welding known as solid state joining process is extensively used in joining of similar and dissimilar 5mm thickness aluminium alloys. The butt-joint types of similar joint (Al5083-Al5083) and dissimilar joint (Al5083-Al6061) were carried out under the same welding parameters, in which the rotation speed was 1000rpm and transverse speed was 100 mm/minute. Macro and microstructure observations were acquired at the transverse cross section of the weld regions respectively by stereo and optical microscope. The microstructural study indicated the spread out of materials mixing between two materials at both sides of welding part. In the similar welding the formation an ‘onion ring’ structure has been detected in the nugget zone, while wavy and distorted patterns appeared in dissimilar joints. The tensile test results showed similar fracture patterns in all tensile specimens for similar welding joint where all fractures occurred in thermo-mechanically affected zone (TMAZ). However, tensile specimens of dissimilar welding joint break up at TMAZ region as well as at Al6061 base metal in retreating side. In comparison the tensile strength of similar joints Al5083-Al5083 and dissimilar joint Al5083-Al6061 were 22% and 19% lower compared to base metal of Al5083 and Al6061, respectively.
2023
Friction Stir Welding is a suitable solid-state joining technology to connect dissimilar materials. To produce an effective joint, a phase of optimization is required which leads to the definition of process parameters such as pin geometry, tool rotational speed, rotation direction, welding speed, thickness of the sheets or tool tilt angle. The aim of this review is to present a complete and detailed frame of the main process parameters and their effect on the final performance of a friction stir welded joint in terms of mechanical properties and microstructure. Attention was focused in particular on the connection between different aluminum alloys. Moreover, the experimental results were correlated to the development and the applications of tools which can be effectively used in the design of the manufacturing process such as finite element analyses, artificial neural networks, and statistical studies. The review also aims to be a point of reference to identify the best combinations of process parameters based on the dissimilar aluminum to be joined.
Jurnal Kejuruteraan, 2023
The friction stir welding (FSW) is widely used in the fabrication of Aluminium alloy and other non-ferrous alloy. It has good potential to be used in major industries such as automobiles, aerospace, shipbuilding and can be used in the joining of high strength alloys. The FSW process low distortion and heat affected zone (HAZ) with fine recrystallized microstructure which leads to better mechanical properties at the weld zone and produces great stability. In this study, the different FSW parameters such as weld speed, tool rotation speed, tool tilt angle, feed per min has been discussed. The different types of tool pin profile and shoulder have also been discussed and their impacts on mechanical and microstructural properties at welded joints. Among various welding parameters the rotational speed is the most influencing parameter in FSW. Increasing the rotational speed exhibits the increase at tensile strength and is supposed to improve the mechanical properties. The most affected tool pin profile would be considered to be tapered threaded cylindrical pin profile which makes the adequate mixing of material with better flow ability and provide the fine grains at nugget zone. Comparing the FSW with other arc welding processes, it shows a wide range of environmental benefits which are noticeable such as saving in consumable materials, decrease in consumption of filler material and reduction in grinding wastes. Harmful emissions created from arc welding causes a health hazard to the welder. For achieving the high joint-strength for aerospace aluminium alloys and high temperature sustainable metallic alloys, friction stir welding will be preferred.
Experimental Investigation of Friction Stir Welding of Aluminium Alloy
The use of aluminum alloys, nowadays, is swiftly growing from the prerequisite of producing higher strength to weight ratio. Lightweight components are crucial interest in most manufacturing sectors, especially in transportation, aviation, maritime, automotive, and others. Traditional available joining methods have an adverse effect on joining these lightweight engineering materials, increasing needs for new environmentally friendly joining methods. Hence, friction stir welding (FSW) is introduced. Friction stir welding is a relatively new welding process that can produce high-quality weld joints with a lightweight and low joining cost with no waste. This paper endeavors to deals with optimizing process parameters for quality criteria on tensile and hardness strengths. Samples were taken from a 5 mm 6061-T6 aluminum alloy sheet with butt joint configuration. Controlled process parameters tool profile, rotational speed and transverse speed were utilized. The process parameters are optimized making use of the combination of Grey relation analysis method and L 9 orthogonal array. Mechanical properties of the weld joints are examined through tensile, hardness, and liquid penetrant tests at room temperature. From this research, rotational speed and traverse speed become significant parameters at a 99% confidence interval, and the joint efficiency reached 91.3%.
FRICTION STIR WELDING PROCESS PARAMETERS FOR JOINING DISSIMILAR ALUMINUM ALLOYS
iaeme
Aluminium alloys have gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to weight ratio and good corrosion resistance. Modern structural concepts demand reductions in both the weight as well as the cost of the production and fabrication of materials. Therefore welding processes have proven more attractive, and there is an urgency to study their potential. Compared to the fusion welding processes that are routinely used for joining structural aluminium alloys, friction stir welding (FSW) process is an emerging solid state joining process was invented in 1991 by TWI, in which the material that is being welded does not melt and recast. The major advantage in FSW process is that the maximum temperature reached is less than 80% of the melting temperature (TM), i.e. the joint is performed in the solid-state and excessive micro structural degradation of the weld zone is avoided. This process uses a non-consumable tool to generate frictional heat in the abutting surfaces. The welding parameters such as tool rotational speed, welding speed, axial force etc., and tool pin profile play a major role in deciding the joint strength. This paper focus on Mechanical properties evaluation and predicting the process parameters in varying rotational and welding speeds of friction-stir welding for the dissimilar precipitation hardenable aluminium alloys ie., between 6xxx (Al-Mg-Si) and 7xxx (Al-Zn-Mg).
International Journal of Engineering Sciences & Research Technology, 2014
In present study, Dissimilar Friction Stir Butt Welds made of 2014 and 6061 Aluminium alloys were performed with various welding parameter. The present study deals with the influence of Square Profile Pin on Friction Stir Welded joint. FSW parameter such as Tool Rotational Speed, Welding Speed and Axial Force plays a significant role in the assessment of mechanical properties. Using ANOVA and Signal to Noise ratio, influence of FSW process parameters is evaluated and optimum welding condition for maximizing mechanical properties of the joint is determined. An Artificial Neural Network (ANN) model was developed for the analysis and simulation of the correlation between the Friction Stir Welding (FSW) parameters of aluminium (Al) plates and mechanical properties and compared the experimental values with the ANN predicted values.