Influence of Friction Stir Welding on Mechanical Properties of Butt Joints of AZ61 Magnesium Alloy

In this study, the effect of heat input on the mechanical properties and fracture behaviors of AZ61 magnesium alloy joints has been studied. Magnesium alloy AZ61 plates with thickness of 5 mm were welded at different ratios of tool rotational speed to welding speed (ω/ν). The average ultimate tensile strength of all weld conditions satisfying a ω/ν ratio of 3 reached 100% of the strength of the base material. Fractures occurred at the interface between the thermomechanical affected zone at advancing side and the stir zone in all welded specimens. From the scanning electron microscope and electron backscatter diffraction analysis, it was determined that the interface between the thermomechanical affected zone and the stir zone, which is the region where the grain orientation changes, was the weakest part; the advancing side region was relatively weaker than the retreating side region because the grain orientation change occurred more dramatically in the advancing side region.

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Effect of rotation speed on microstructure and mechanical properties of bobbin tool friction stir welded AZ61 magnesium alloy

Science and Technology of Welding & Joining ◽

10.1080/13621718.2018.1432098 ◽

2018 ◽

Vol 23 (7) ◽

pp. 596-605 ◽

Cited By ~ 16

Author(s):

L. Zhou ◽

G. H. Li ◽

G. D. Zha ◽

F. Y. Shu ◽

H. J. Liu ◽

...

Keyword(s):

Mechanical Properties ◽

Magnesium Alloy ◽

Rotation Speed ◽

Friction Stir ◽

Az61 Magnesium Alloy ◽

Microstructure And Mechanical Properties

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Research on the Friction Stir Welding of Sc-Modified AA2519 Extrusion

Metals ◽

10.3390/met9101024 ◽

2019 ◽

Vol 9 (10) ◽

pp. 1024 ◽

Cited By ~ 5

Author(s):

Robert Kosturek ◽

Lucjan Śnieżek ◽

Janusz Torzewski ◽

Marcin Wachowski

Keyword(s):

Mechanical Properties ◽

Friction Stir Welding ◽

Base Material ◽

Stir Zone ◽

Welding Parameters ◽

Friction Stir ◽

Treated Condition ◽

Heat Treated ◽

Heat Treated Condition ◽

Fsw Parameters

The aim of this research was to investigate the effect of friction stir welding (FSW) parameters on microstructure and mechanical properties of Sc-modified AA2519 extrusion joints. The workpiece was welded by FSW in non-heat-treated condition with seven different sets of welding parameters. For each obtained joint macrostructure and microstructure observations were performed. Mechanical properties of joints were investigated using tensile test together with localization of fracture location. Joint efficiencies were established by comparing measured joints tensile strength to the value for base material. The obtained results show that investigated FSW joints of Sc-modified AA2519 in the non-heat-treated condition have joint efficiency within the range 87–95%. In the joints obtained with the lowest ratio of the tool rotation speed to the tool traverse speed, the occurrence of imperfections (voids) localized in the stir zone was reported. Three selected samples were subjected to further investigations consisting microhardness distribution and scanning electron microscopy fractography analysis. As the result of dynamic recrystallization, the microhardness of the base material value of 86 HV0.1 increased to about 110–125 HV0.1 in the stir zone depending on the used welding parameters. Due to lack of the strengthening phase and low strain hardening of used alloy the lack of a significantly softened zone was reported by both microhardness analysis and investigation of the fractured samples.

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Effect of Ca addition on the microstructure and the mechanical properties of asymmetric double-sided friction stir welded AZ61 magnesium alloy

Journal of Magnesium and Alloys ◽

10.1016/j.jma.2020.02.001 ◽

2020 ◽

Vol 8 (1) ◽

pp. 91-102 ◽

Cited By ~ 10

Author(s):

Mengran Zhou ◽

Yoshiaki Morisada ◽

Hidetoshi Fujii

Keyword(s):

Mechanical Properties ◽

Magnesium Alloy ◽

Friction Stir ◽

Az61 Magnesium Alloy ◽

Ca Addition

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Effect of Enhanced Cooling on the Microstructure and Mechanical Properties of Friction Stir Spot-Welded AZ31 Magnesium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.850.784 ◽

2016 ◽

Vol 850 ◽

pp. 784-789

Author(s):

Song Lin Chen ◽

Da Tong Zhang

Keyword(s):

Mechanical Properties ◽

Magnesium Alloy ◽

Cooling Water ◽

Stir Zone ◽

Az31 Magnesium Alloy ◽

Air Cooling ◽

Friction Stir ◽

Microstructure And Mechanical Properties ◽

Average Grain Size ◽

Spot Welded

AZ31 magnesium alloy was friction stir spot welded in air and cooling in water. The effect of the enhanced cooling rate on the microstructure and mechanical properties of the joint was analyzed. The results showed that flowing water had obvious cooling effect instantaneously, which significantly restrained the growth of dynamic recrystallized grains. The average grain size in stir zone was 1.3μm in cooling water condition, which is far smaller than that of the joint prepared in air cooling condition. Under the condition of enhanced cooling, the microhardness in stir zone significantly increased, the ultimate tensile load (~ 3.99kN) increased by 15.7%, and the tensile deformation value (~ 3.65 mm) increased by 62.2%. Dimples in SEM fracture morphologies indicated the better plastic deformation capacity of joints prepared by cooling water, which failed through a mixture mode of ductile and brittle fracture.

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Investigation of Microstructure and Mechanical Properties of Friction Stir Lap Jointed Ni Base Superalloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.724.481 ◽

2012 ◽

Vol 724 ◽

pp. 481-485

Author(s):

Kuk Hyun Song ◽

Kazuhiro Nakata

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Friction Stir Welding ◽

Base Material ◽

Lap Joints ◽

Stir Zone ◽

Inconel 600 ◽

Friction Stir ◽

Microstructure And Mechanical Properties ◽

Average Grain Size

This study evaluated the microstructure and mechanical properties of friction stir welded lap joints. Inconel 600 and SS 400 as experimental materials were selected, and friction stir welding was carried out at tool rotation speed of 200 rpm and welding speed of 100 mm/min. Applying the friction stir welding was notably effective to reduce the grain size of the stir zone, as a result, the average grain size of Inconel 600 was reduced from 20 μm in the base material to 8.5 μm in the stir zone. Joint interface between Inconel 600 and SS 400 showed a sound weld without voids and cracks. Also, the hook, along the Inconel 600 alloy from SS 400, was formed at advancing side, which directly affected an increase in peel strength. In this study, we systematically discussed the evolution on microstructure and mechanical properties of friction stir lap jointed Inconel 600 and SS 400.

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Enhancing mechanical properties of AZ61 magnesium alloy via friction stir processing: Effect of processing parameters

Materials Science and Engineering A ◽

10.1016/j.msea.2020.139945 ◽

2020 ◽

Vol 797 ◽

pp. 139945 ◽

Cited By ~ 1

Author(s):

X.C. Luo ◽

L.M. Kang ◽

H.L. Liu ◽

Z.J. Li ◽

Y.F. Liu ◽

...

Keyword(s):

Mechanical Properties ◽

Magnesium Alloy ◽

Friction Stir Processing ◽

Processing Parameters ◽

Friction Stir ◽

Processing Effect ◽

Az61 Magnesium Alloy

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Effects of welding speeds on the microstructural and mechanical properties of AZ91D Mg alloy by friction stir welding

International Journal of Structural Integrity ◽

10.1108/ijsi-12-2019-0131 ◽

2020 ◽

Vol 11 (6) ◽

pp. 769-782 ◽

Cited By ~ 1

Author(s):

Nagabhushan Kumar Kadigithala ◽

Vanitha C

Keyword(s):

Mechanical Properties ◽

Friction Stir Welding ◽

Magnesium Alloy ◽

Welding Speed ◽

Base Material ◽

Welding Parameters ◽

Content Type ◽

Friction Stir ◽

Az91d Magnesium Alloy ◽

Transverse Tensile

PurposeThe main purpose of the present work is to evaluate, the microstructural and mechanical properties of friction stir welded plates of AZ91D magnesium alloy with 3 mm thickness, and to determine the optimum range of welding conditions.Design/methodology/approachMicrostructure and fractographic studies were carried out using scanning electron microscopy (SEM). Vickers micro hardness test was performed to evaluate the hardness profile in the region of the weld area. The phases in the material were confirmed by X-Ray diffraction (XRD) analysis. Transverse tensile tests were conducted using universal testing machine (UTM) to examine the joint strength of the weldments at different parameters.FindingsMetallographic studies revealed that each zone shown different lineaments depending on the mechanical and thermal conditions. Significant improvement in the hardness was observed between the base material and weldments. Transverse tensile test results of weldments had shown almost similar strength that of base material regardless of welding speed. Fractographic examination indicated that the welded specimens failed due to brittle mode fracture. Through these studies it was confirmed that friction stir welding (FSW) can be used for the welding of AZ91D magnesium alloy.Research limitations/implicationsIn the present study, the welding speed varied from 25 mm/min to 75 mm/min, tilt angle varied from 1.5° to 2.5° and constant rotational speed of 500 rpm.Practical implicationsMagnesium and aluminum based alloys which are having high strength and low density, used in automotive and aerospace applications can be successfully joined using FSW technique. The fusion welding defects can be eliminated by adopting this technique.Originality/valueLimited work had been carried out on the FSW of magnesium based alloys over aluminum based alloys. Furthermore, this paper analyses the influence of welding parameters over the microstructural and mechanical properties.

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