scholarly journals Study the effect of welding pass number on the mechanical and metallurgical properties of Aluminum type Al 1050 H14 produced by friction stir welding

2021 ◽  
Vol 28 (4) ◽  
pp. 1-13
Author(s):  
Najeeb Salman Abtan ◽  
Jawdat Ali Yagoob ◽  
Ayshan Mohammed Shukri

Friction Stir Welding (FSW) is a solid-state welding technique with non-fusible rotary welds. Heat is generated by the friction produced between the weld tool and the two opposite surfaces of the two welded parts and the tool works on mechanical mixing with the presence of heat, pressure, and heat generated, reaching approximately (80-90%) of the melting point of the metal to be welded. In this study, Al 1050 H14 aluminum with a thickness of (6mm) was used for the purpose of welding it by means of the friction stir welding process in a butt welding method to obtain similar welding joints. A set with a square stitching tool Made of alloy steel was used by using a milling machine, with fixed (rotational speed of 1008 rpm and linear velocity of 40mm / min), an inclination angle of (2o), and counterclockwise rotation. The efficiency of welded joints was evaluated through static mechanical tests. Tensile tests, microscopic hardness, and visual examination. The results for all welds showed that the mixing zone (NZ) consists of fine grains of equal axes compared to the base metal. When welding on one side and in one path, the microstructure of HAZ was similar to the base metal. TAMZ was a transition region between HAZ and NZ. As for welding on one side, with two paths and three paths, the structure turned into a fine crystalline structure. By increasing the number of paths per side, the welding efficiency of the welded sample increased as the best efficiency was from one side and three paths (76.215%). Through the results, the tensile strength increases with the increase in the number of paths, as the best tensile strength was obtained when conducting the welding process from one side and by three paths, which is (93.653 MPa). It is equivalent to 76.21% of the tensile strength of the base metal. The hardness value in the weld zone (NZ) is higher than the other two zones (HAZ, TMAZ) due to the occurrence of dynamic recrystallization, which results in very fine and equiaxial crystals, but the hardness value in the weld zone remains less than the hardness value of the base metal.

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
R. Suryanarayanan ◽  
V. G. Sridhar ◽  
L. Natrayan ◽  
S. Kaliappan ◽  
Anjibabu Merneedi ◽  
...  

Friction stir welding is a solid-state welding method that produces joints with superior mechanical and metallurgical properties. However, the negative effects of the thermal cycle during welding dent the mechanical performance of the weld joint. Hence, in this research study, the joining of aluminum tailor welded blanks by friction stir welding is carried out in underwater conditions by varying the welding parameters. The tensile tests revealed that the underwater welded samples showed better results when compared to the air welded samples. Maximum tensile strength of 229.83 MPa was obtained at 1000 rpm, 36 mm/min. The improved tensile strength of the underwater welded samples was credited to the suppression of the precipitation of the secondary precipitates due to the cooling action provided by the water. The lowest hardness of 72 HV was obtained at the edge of the stir zone which indicated the weakest region in the weld zone.


2018 ◽  
Vol 32 (9) ◽  
pp. 1242-1267 ◽  
Author(s):  
Hossain Ahmed ◽  
MJL van Tooren ◽  
Jonathan Justice ◽  
Ramy Harik ◽  
Addis Kidane ◽  
...  

The joining of thermoplastics through welding offers numerous advantages over mechanical joining. Most importantly, it eliminates the use of costly fasteners and has only a limited effect on the strength of the parts being joined. Since it does not require the introduction of holes, loading pins, and the associated stress concentrations, a specific form of welding, friction stir welding (FSW), was investigated for the creation of butt joints of unreinforced polyphenylene sulfide (PPS) and short carbon fiber (CF)-reinforced polyetheretherketone (PEEK) plates. Unlike metals, analytical models and experimental results show that the heat generated by the FSW tool is insufficient to produce the heat required to weld thermoplastic materials. Therefore, a second heat source is required for preheating these thermoplastics. In this research, a resistance type surface heater was placed at the bottom of two identical weld pieces to produce good quality welds. Two types of shoulder design such as rotating shoulder and stationary shoulder were developed in this study. Taguchi’s design of experiment method was utilized to develop the welding process, where heating duration, material temperature, tool rotational speed, and tool traverse speed were used as the welding parameters. One of the process parameters, tool traverse speed, had significant influence on the tensile strength of PPS samples. While PPS sample showed relatively lower tensile strength with higher traverse speed, short CF-reinforced PEEK samples had higher tensile strength with a higher traverse speed. In addition to tensile tests, fracture toughness tests were performed for both PPS and PEEK samples to observe the influence of unwelded segments in the welded parts. In this study, joint efficiency of PEEK samples was found to be higher than that of PPS samples. Micrographs of PEEK samples showed uniform homogenous mixture of part materials.


2021 ◽  
Author(s):  
Eyob Messele ◽  
Assefa Asmare Tsegaw

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.


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.


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.


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.


2019 ◽  
Vol 269 ◽  
pp. 02006
Author(s):  
Li Fu ◽  
Fenjun Liu

Al-Mg-Si (6061-T6) alloy with 0.8 mm thick plate was welded successfully by use of high speed friction stir welding (FSW) technology. The microstructural characteristics and mechanical property of the butt joints prepared by high speed FSW were analyzed in detail, the influence of welding parameters, fixture condition and after welding heat treatment were also explored. The results shown that sound surface topography and defect-free bonding interface were observed in the nugget zone (NZ). The microhardness of the as-welded joint was lower than that of the base metal because of the welding heat effect. Compared with the conventional speed FSW, the number of β-Mg2Si, Al2CuMg and Al8Fe2Si precipitated phases existed in the high speed FSWed NZ increased, which made the microhardness in the NZ improved significantly. The rod-shaped precipitates (Mg2Si) have the greatest influence on the microhardness distributions. The maximum tensile strength of 301.8 MPa, which was 85.8% of the base metal, was obtained at high rotation speed of 8000 rpm and fast welding speed of 1500 mm/min. The tensile strength of the ultra-high speed FSWed butt joints were improved significantly by post-weld artificial aging, with a maximum joint efficiency of 90.4%.


2019 ◽  
Vol 969 ◽  
pp. 828-833 ◽  
Author(s):  
R. Nandhini ◽  
R. Dinesh Kumar ◽  
S. Muthukumaran ◽  
S. Kumaran

The friction stir welding of polyamide 66 with a specially modified tool is studied. A variation of the conventional friction stir welding is investigated by incorporating a friction plate for the purpose of heating the polymer in the course of welding process through the tool shoulder. This in turn, improves the efficiency of the weld. The association of the welding process parameters and the weld performance has been investigated by the grey relational analysis with multi response characteristics like weld tensile strength, percent elongation and hardness. Macrostructure of the weld joint cross section has been explored by Stereo microscope. The maximum weld tensile strength of 63 MPa and a Shore hardness of 60 D at the weld nugget are obtained. The hardness profiles of the welded samples have been analyzed in this investigation.


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