scholarly journals Microstructure and Mechanical Properties of Friction Stir-Welded Dissimilar Joints of ZK60 and Mg-4.6Al-1.2Sn-0.7Zn Alloys

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 23
Author(s):  
Liangwen Xie ◽  
Xianyong Zhu ◽  
Yuexiang Fan ◽  
Weijia Sun ◽  
Peng Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Welded Joints ◽  
Gradual Increase ◽  
Tensile Fracture ◽  
Dissimilar Joints ◽  
Friction Stir ◽  
Base Materials ◽  
Transverse Tensile ◽  
Better Than

In order to clarify the microstructural evolution and the mechanical property of dissimilar friction stir-welded joints of ZK60 and Mg-4.6Al-1.2Sn-0.7Zn magnesium alloys, two types of arrangement with ZK60 at advancing side (AS) or retreating side (RS) were adopted. The macrostructure and the microstructure of the dissimilar welded joints were discussed, and the microhardness and the transverse tensile properties of the joints were measured. There are three stirring sub-zones with different compositions and two clear interfaces within the joints. Due to the effect of both the original grain size of base materials and the growth of recrystallized grains, in the stir zone (SZ), the grain size of ZK60 increased slightly, while the grain size of Mg-4.6Al-1.2Sn-0.7Zn decreased significantly. The dissolution of precipitates was gradually significant from RS to AS within the SZ due to the gradual increase in strain and heat. The grain refinement led to an increase in hardness, while the dissolution of precipitates resulted in a decrease in hardness. The performance of the joints obtained with ZK60 placed on the RS is slightly better than that of that on the AS. The tensile fracture of both joints occurred at the interface between SZ and the thermos-mechanical affected zone at the AS, and showed a quasi-dissociative fracture.

scholarly journals Metallurgical and Mechanical Characterization of High-Speed Friction Stir Welded AA 6082-T6 Aluminum Alloy

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4211 ◽  
Author(s):  
Anton Naumov ◽  
Iuliia Morozova ◽  
Evgenii Rylkov ◽  
Aleksei Obrosov ◽  
Fedor Isupov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Welding Speed ◽  
Welded Joints ◽  
High Speed ◽  
Structural Characteristics ◽  
Tensile Fracture ◽  
Friction Stir ◽  
Microhardness Distribution ◽  
Aluminum Sheets

The objective of this study was to investigate the effect of the high welding speed on the mechanical properties and their relations to microstructural characteristics of butt friction stir welded joints with the use of 6082-T6 aluminum alloy. The aluminum sheets of 2.0 mm thick were friction stir welded at low (conventional FSW) and high welding speeds (HSFSW) of 200 and 2500 mm/min, respectively. The grain size in the nugget zone (NZ) was decreased; the width of the softened region was narrowed down as well as the lowest microhardness value located in the heat-affected zone (HAZ) was enhanced by HSFSW. The increasing welding speed resulted in the higher ultimate tensile strength and lower elongation, but it had a slight influence on the yield strength. The differences in mechanical properties were explained by analysis of microstructural changes and tensile fracture surfaces of the welded joints, supported by the results of the numerical simulation of the temperature distribution and material flow. The fracture of the conventional FSW joint occurred in the HAZ, the weakest weld region, while all HSFSW joints raptured in the NZ. This demonstrated that both structural characteristics and microhardness distribution influenced the actual fracture locations.

Investigations on microstructural and mechanical properties of friction stir welded AA 2024-T351

2020 ◽  
Vol 62 (8) ◽  
pp. 793-802
Author(s):  
Şefika Kasman ◽  
Sertan Ozan
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Rotational Speed ◽  
Stir Zone ◽  
Tool Rotational Speed ◽  
Friction Stir ◽  
Aa 2024

Abstract In the present study, AA 2024-T351 plates with a thickness of 6 mm were joined using the friction stir welding technique with three different tool rotational speeds and two different pin profiles. Microstructural features and mechanical properties of welded joints were investigated. The grains in recrystallized regions along the stir zone were observed to be almost with invariable sizes. The grain size was revealed to increase with the increase in tool rotational speed. The average grain size was observed to dramatically increase from 2.3 μm to 5.6 μm for welded joints produced with pentagonal shaped pin. All the welded joints were observed to contain defects; the presence of defects exhibited a negative effect on the tensile properties of the welded joint. Most of the defects were observed to localize at the root region of joints. The joint, welded with the tool rotational speed of 250 rpm using pentagonal shaped pin, exhibited ultimate tensile strength with a value of 365 MPa. The ultimate tensile strength of welded joints was found to be higher with the decrease in the tool rotational speed. The welding efficiency of joints was compared with the ultimate tensile strength of base metal; notably, welding efficiency values between 46 % and 80 % were achieved. Microstructural characterizations revealed that Al2Cu (θ phase), Al2CuMg (S phase), and AlCuFeMnSi, Al7Cu2Fe intermetallic particles were dispersed in the stir zone.

ANALYSIS AND CHARACTERIZATION OF FORMING BEHAVIOR ON DISSIMILAR JOINTS OF AA5052-O TO AA6061-T6 USING UNDERWATER FRICTION STIR WELDING

2019 ◽  
Vol 27 (03) ◽  
pp. 1950121
Author(s):  
K. TEJONADHA BABU ◽  
S. MUTHUKUMARAN ◽  
C. SATHIYA NARAYANAN ◽  
C. H. BHARAT KUMAR
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Strain Hardening ◽  
Welded Joints ◽  
Dissimilar Materials ◽  
Strain Hardening Exponent ◽  
Dissimilar Joints ◽  
Friction Stir ◽  
Joint Efficiency ◽  
Underwater Friction Stir Welding

The effects of underwater friction stir welding (UFSW) on mechanical properties, strain hardening behavior, and formability of dissimilar materials of AA5052-O and AA6061-T6 welded joints were investigated. The mechanical properties of the UFSW joints exhibited higher strength and higher joint efficiency than the conventional friction stir welded joints (CFSW). The maximum joint efficiency of 73% has been attained for UFSW joints, which is due to the effect of welding atmosphere. The hardness of the stir zone (SZ) and heat affected zone (HAZ) are also obtained higher for the UFSW joints. Moreover, the hardening capacity, strain hardening exponent and formability of the UFSW joints were greatly improved over the CFSW joints. The improvement in mechanical properties of the UFSW joints is mainly due to faster cooling rate during welding. The microstructural characteristics revealed the formation of fine grains in the UFSW joints compared to the CFSW joints.

scholarly journals Mechanical and Wear Properties of Friction Stir Welded 0–6Wt% nAl2O3 Reinforced Al-13Wt%Si Composites

2017 ◽  
Vol 67 (1) ◽  
pp. 77-86 ◽  
Author(s):  
Vinay Kumar Patel ◽  
Komal Rani
Keyword(s):  
Tensile Strength ◽  
Welded Joints ◽  
Sliding Wear ◽  
Base Material ◽  
Wear Properties ◽  
Alloy Matrix ◽  
Friction Stir ◽  
Base Materials ◽  
Nano Alumina ◽  
Better Than

Abstract Friction Stir Welding (FSW) of an Al-13%Si alloy matrix reinforced with 0, 3 and 6 wt% Al2O3 nanoparticles (nAl2O3) is performed and the optical microstructures, tensile strength, hardness and sliding wear properties of friction stir welded joints are investigated and compared to those of base materials. Four different zones of distinct appearances were observed during FSW, which exhibited altered microstructures in the nugget zone (NZ), thermo mechanically affected zone (TMAZ), heat affected zone (HAZ), and base material zone (BMZ). The ultimate tensile strength of the base materials and their welded joints were found to be increasing with increased wt% of nano-alumina reinforcements. High joint efficiency of 89-97% was achieved in FSW. Hardness and wear resistance of friction stir welded joints were found to be better than those of the base materials.

Vibratory weld conditioning during gas tungsten arc welding of al 5052 alloy on the mechanical and micro-structural behavior

2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Welded Joints ◽  
Great Influence ◽  
Welding Process ◽  
Microstructural Characterization ◽  
Content Type ◽  
Average Grain Size

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.

Effect of Intermetallic Compound Phases on the Mechanical Properties of the Dissimilar Al/Cu Friction Stir Welded Joints

2016 ◽  
Vol 25 (11) ◽  
pp. 4637-4648 ◽  
Author(s):  
S. A. Khodir ◽  
M. M. Z. Ahmed ◽  
Essam Ahmed ◽  
Shaymaa M. R. Mohamed ◽  
H. Abdel-Aleem
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compound ◽  
Welded Joints ◽  
Friction Stir

The Use of Bobbin Tools for Friction Stir Welding of Aluminium Alloys

2010 ◽  
Vol 638-642 ◽  
pp. 1179-1184 ◽  
Author(s):  
Philip L. Threadgill ◽  
M.M.Z. Ahmed ◽  
Jonathan P. Martin ◽  
Jonathan G. Perrett ◽  
Bradley P. Wynne
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Friction Stir Welding ◽  
Cross Section ◽  
Axial Force ◽  
Aluminium Alloys ◽  
Processing Parameters ◽  
Machine Design ◽  
Friction Stir ◽  
Triangular Zone

The use of a double sided friction stir welding tool (known as a bobbin tool) has the advantage of giving a processed zone in the workpiece which is more or less rectangular in cross section, as opposed the triangular zone which is more typically found when conventional friction stir welding tool designs are used. In addition, the net axial force on the workpiece is almost zero, which has significant beneficial implications in machine design and cost. However, the response of these tools in generating fine microstructures in the nugget area has not been established. The paper presents detailed metallographic analyses of microstructures produced in 25mm AA6082-T6 aluminium wrought alloy, and examines grain size, texture and mechanical properties as a function of processing parameters and tool design, and offers comparison with data from welds made with conventional tools.

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