Enhancements on dissimilar friction stir welding between AZ31 and SPHC mild steel with Al-Mg as powder additives

Author(s):  
Mohd Ridha Muhamad ◽  
Sufian Raja ◽  
Mohd Fadzil Jamaludin ◽  
Farazila Yusof ◽  
Yoshiaki Morisada ◽  
...  

Abstract Dissimilar materials joining between AZ31 magnesium alloy and SPHC mild steel with Al-Mg powder additives were successfully produced by friction stir welding process. Al-Mg powder additives were set in a gap between AZ31 and SPHC specimen's butt prior to welding. The experiments were performed for different weight percentages of Al-Mg powder additives at welding speeds of 25 mm/min, 50 mm/min and 100 mm/min with a constant tool rotational speed of 500 rpm. The effect of powder additives and welding speed on tensile strength, microhardness, characterization across welding interface and fracture morphology were investigated. Tensile test results showed significant enhancement of tensile strength of 150 MPa for 10% Al and Mg (balance) powder additives welded joint as compared to the tensile strength of 125 MPa obtained for welded joint without powder additives. The loss of aluminium in the alloy is compensated by Al-Mg powder addition during welding under a suitable heat input condition identified by varying welding speeds. Microstructural analysis revealed that the Al-Mg powder was well mixed and dispersed at the interface of the joint at a welding speed of 50 mm/min. Intermetallic compound detected in the welding interface contributed to the welding strength.

2011 ◽  
Vol 189-193 ◽  
pp. 3266-3269 ◽  
Author(s):  
Yu Hua Chen ◽  
Peng Wei ◽  
Quan Ni ◽  
Li Ming Ke

Titanium alloy TC1 and Aluminum alloy LF6 were jointed by friction stir welding (FSW), and the influence of process parameters on formation of weld surface, cross-section morphology and tensile strength were studied. The results show that, Titanium and Aluminum dissimilar alloy is difficult to be joined by FSW, and some defects such as cracks and grooves are easy to occur. When the rotational speed of stir head(n) is 750r/min and 950r/min, the welding speed(v) is 118mm/min or 150mm/min, a good formation of weld surface can be obtained, but the bonding of titanium/aluminum interface in the cross-section of weld joint is bad when n is 750r/min which results in a low strength joint. When n is 950r/min and v is 118mm/min,the strength of the FSW joint of Titanium/Aluminum dissimilar materials is 131MPa which is the highest.


2020 ◽  
Vol 40 (1) ◽  
pp. 67-74
Author(s):  
Manigandan Krishnan ◽  
Senthilkumar Subramaniam

The force generation, joint mechanical and metallurgical properties of friction stir corner welded non-heat treatable AA 5086 aluminum alloy are investigated in this paper. The friction stir welding process is carried out with the plate thicknesses of 6 mm and 4 mm. The welding speed, tool rotational speed and tool plunge depth were considered as the process parameters to conduct the welding experiments. The machine spindle motor current consumption and tool down force generation during friction stir welding were analyzed. The microstructures of various joint regions were observed. The tensile samples revealed the tensile strength of 197 MPa with tool rotational and welding speeds of 1,000 rev/min and 150 mm/min respectively, which is 78 % of parent material tensile strength. A maximum micro hardness of 98 HV was observed at thermomechanically joint affected zone, which was welded with tool rotation of 1,000 rev/min and welding speed of 190 mm/min.


2018 ◽  
Vol 26 (4) ◽  
pp. 1-17
Author(s):  
Samir Ali Amin ◽  
Mohannad Yousif Hanna ◽  
Alhamza Farooq Mohamed

Bobbin friction stir welding (BFSW) is special kind of friction stir welding. This investigation aims to develop empirical models through mathematical relationships between the welding process parameters and mechanical properties of Aluminum alloy AA6061-T6 welded joint created by using bobbin tool and to find the optimum welding parameters. The welding speed range (40-200 mm/min) and rotational speed range (340-930 rpm) were utilized (as the used input factors) to find their effects on elongation, tensile strength and maximum bending force as the main responses.  These models were built using Design of Experiment (DOE) software ‘version 10’ with Response Surface Methodology (RSM) technique. The models adequacy were tested via the (ANOVA) analysis. The obtained models appeared that as the welding speed or rotational speed increases, the elongation, tensile strength and maximum bending force of the welded joint firstly rise to a maximum value and then drop. The optimum welding parameters were rotational speed (623.949 rpm) and welding speed (128.795 mm/min) with (6.33%), (204 MPa) and (6.216 KN) of elongation, tensile strength and maximum bending force, respectively. A proper harmonization was obtained between the models predicted results and the optimized ones with actual trial with 95% level of confidence.


Author(s):  
Nidhi Sharma ◽  
Zahid A Khan ◽  
Arshad Noor Siddiquee ◽  
Mohd Atif Wahid

Friction stir welding is a new and effective solid-state welding process for joining dissimilar materials such as aluminum (Al) and copper (Cu). Joint quality of the friction stir welded materials gets influenced by the welding strategy and different friction stir welding process parameters, i.e. rotational speed, welding speed, tool design, tool pin offset, and tilt angle. In this paper, the effect of combination of different friction stir welding process parameters during joining of Al-6101 and pure copper is studied using Taguchi L18 orthogonal array. Four friction stir welding process parameters, i.e. shoulder diameter (A), pin offset (B), welding speed (C), and rotational speed (D) each at three levels except shoulder diameter, which is at two levels are selected. The effect of different combinations of these parameters on ultimate tensile strength and micro-hardness of the joints is investigated. Subsequently, single response optimization for ultimate tensile strength and micro-hardness and multi-response optimization of ultimate tensile strength and micro-hardness taken together is carried out to obtain the optimal combination of the friction stir welding process parameters. Taguchi method is used for single response optimization, whereas Taguchi-based TOPSIS method is employed for multi-response optimization. For single optimization, the optimum combination of the friction stir welding parameters yielding maximum strength and micro-hardness are A1B1C2D2 and A2B1C2D3, respectively. The optimum combination of the process parameters for multi-response optimization is A2B1C2D2. From the results of the study for single- and multi-response optimization, it is revealed that the rotational speed is the most significant process parameter affecting the tensile strength and micro-hardness of the joints followed by the welding speed. Further, the macro/microstructure and micro-hardness profile of the joint obtained at the optimal combination of the multi-response optimization are given and discussed for better understanding of material mixing and joining.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
S. Jayaprakash ◽  
S. Siva Chandran ◽  
T. Sathish ◽  
Bhiksha Gugulothu ◽  
R. Ramesh ◽  
...  

Friction stir welding is an innovative welding process for similar and dissimilar joining of the materials effectively. FSW simply modified the grain structure and also improved the strength of the joints for any type of alloying elements. This experimental study planned to carry out the joining process for dissimilar materials such as aluminium alloys 5083 and 7068. Three different types of tools are involved to find the ultimate tensile strength and Vickers hardness. The tool types are straight cylindrical tool, taper cylindrical tool, and triangular tool. The process factors for this investigation are a rotational speed of 800, 1000, 1200, and 1400 rpm, welding speed of 30, 40, 50, and 60 mm/min, axial force of 3, 4, 5, and 6 kN, and plate thickness of 5, 6, 7, and 8 mm. The hardness value and the ultimate tensile strength were increased in the welding zone, which proves the effects of tool profiles are efficiently utilized.


Author(s):  
Sanjeev Verma ◽  
Vinod Kumar

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.


2012 ◽  
Vol 622-623 ◽  
pp. 323-329
Author(s):  
Ebtisam F. Abdel-Gwad ◽  
A. Shahenda ◽  
S. Soher

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.


2021 ◽  
Vol 23 (2) ◽  
pp. 98-115
Author(s):  
Alexey Ivanov ◽  
◽  
Valery Rubtsov ◽  
Andrey Chumaevskii ◽  
Kseniya Osipovich ◽  
...  

Introduction. One of friction stir welding types is the bobbin friction stir welding (BFSW) process, which allows to obtain welded joints in various configurations without using a substrate and axial embedding force, as well as to reduce heat loss and temperature gradient across the welded material thickness. This makes the BFSW process effective for welding aluminum alloys, which properties are determined by their structural-phase state. According to research data, the temperature and strain rate of the welded material have some value intervals in which strong defect-free joints are formed. At the same time, much less attention has been paid to the mechanisms of structure formation in the BFSW process. Therefore, to solve the problem of obtaining defect-free and strong welded joints by BFSW, an extended understanding of the basic mechanisms of structure formation in the welding process is required. The aim of this work is to research the mechanisms of structure formation in welded joint of AA2024 alloy obtained by bobbin tool friction stir welding with variation of the welding speed. Results and discussion. Weld formation conditions during BFSW process are determined by heat input into a welded material, its fragmentation and plastic flow around the welding tool, which depend on the ratio of tool rotation speed and tool travel speed. Mechanisms of joint formation are based on a combination of equally important processes of adhesive interaction in “tool-material” system and extrusion of metal into the region behind the welding tool. Combined with heat dissipation conditions and the configuration of the “tool-material” system, this leads to material extrusion from a welded joint and its decompaction. This results in formation of extended defects. Increasing in tool travel speed reduce the specific heat input, but in case of extended joints welding an amount of heat released in joint increases because of specific heat removal conditions. As a result, the conditions of adhesion interaction and extrusion processes change, which leads either to the growth of existing defects or to the formation of new ones. Taking into account the complexity of mechanisms of structure formation in joint obtained by BFSW, an obtaining of defect-free joints implies a necessary usage of various nondestructive testing methods in combination with an adaptive control of technological parameters directly in course of a welding process.


2018 ◽  
Vol 178 ◽  
pp. 03003 ◽  
Author(s):  
Ana Bosneag ◽  
Marius Adrian Constantin ◽  
Eduard Niţu ◽  
Monica Iordache

Friction Stir Welding, abbreviated FSW is a new and innovative welding process. This welding process is increasingly required, more than traditional arc welding, in industrial environment such us: aeronautics, shipbuilding, aerospace, automotive, railways, general fabrication, nuclear, military, robotics and computers. FSW, more than traditional arc welding, have a lot of advantages, such us the following: it uses a non-consumable tool, realise the welding process without melting the workpiece material, can be realised in all positions (no weld pool), results of good mechanical properties, can use dissimilar materials and have a low environmental impact. This paper presents the results of experimental investigation of friction stir welding joints to three dissimilar aluminium alloy AA2024, AA6061 and AA7075. For experimenting the value of the input process parameters, the rotation speed and advancing speed were kept the same and the position of plates was variable. The exit date recorded in the time of process and after this, will be compared between them and the influence of position of plate will be identified on the welding seams properties and the best position of plates for this process parameters and materials.


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