A Review: Effect of Friction Stir Welding on Microstructure and Mechanical Properties of Magnesium Alloys

In the current scenario, the light-weighting concept is the most important strategy to decrease fuel consumption as well as emissions of greenhouse gases. Magnesium alloys are attractive to various industries including transportation industry for their inherent light-weight. The friction stir welding is proficient to join magnesium alloys. In this article, a dissimilar friction stir welding butt joint between AZ31 and AZ61 magnesium alloys was fabricated, and microstructure and mechanical properties have been examined. The tool rotation speed of 1400 r/min and tool transverse feed rate of 25 mm/min was found quite suitable to fabricate a perfect joint of these dissimilar magnesium alloys. The stir zone was composed of fine and equiaxed grains and showed the highest microhardness value. In the advancing side, heat affected zone was composed of both equiaxed and elongated grains; however, in the retreating side, heat affected zone has relatively smooth grains. The tensile strength of the joint was about 138.37 ± 6.6 MPa. The efficiency of the joint was 51.25% with respect to AZ61 Mg alloy. The average impact toughness of friction stir welding joint was deteriorated by 16.67% and 28.5% with respect to base materials AZ31 and AZ61, respectively.

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Influence of post welding heat treatment on the microstructure and mechanical properties of friction stir welding joint of AZ31 Mg alloy

Proceedings of the Institution of Mechanical Engineers Part E Journal of Process Mechanical Engineering ◽

10.1177/0954408921997626 ◽

2021 ◽

pp. 095440892199762

Author(s):

Kulwant Singh ◽

Gurbhinder Singh ◽

Harmeet Singh

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Tensile Strength ◽

Friction Stir Welding ◽

Magnesium Alloys ◽

Tensile Failure ◽

Mg Alloy ◽

Friction Stir ◽

Microstructure And Mechanical Properties ◽

Az31 Mg Alloy

At present, magnesium alloys are extensively used in numerous applications due to their light weight and better characteristics. Welding of magnesium alloys is regarded as one of the most complex phenomena in various industries. The friction stir welding of magnesium alloys has encouraged abundant scientific and industrial interest as it has the potency to form a good quality joint. Post welding heat treatment is an appropriate process to further improve the properties or performance of FSW joints. Therefore, the present work aims to join AZ31 Mg alloy plates by friction stir welding, and microstructural and mechanical properties of the joint have been examined. Furthermore, the consequence of post welding heat treatment on the microstructure and mechanical properties of FSW joint has been evaluated. Tensile strength and elongation of FSW joint were about 145.4 ± 4.9 MPa and 9.5 ± 0.9%, respectively. It was found that post welding heat treatment was beneficial in homogenizing grains and to enhance mechanical properties. Tensile strength and elongation of the joint were improved by 4.74% and 15.78% respectively after PWHT. The highest microhardness of stir zone decreased about 6.84% (73 Hv to 68 Hv) after heat treatment and hardness pattern of weld became relatively smooth. Toughness of PWHT joint was 4.5 ± 0.17 Joules. The mode of tensile failure of as-welded and PWHT joint was ductile.

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Applicability of unique scarf joint configuration in friction stir welding of AA6061-T6: Analysis of torque, force, microstructure and mechanical properties

Defence Technology ◽

10.1016/j.dt.2021.03.010 ◽

2021 ◽

Author(s):

Durjyodhan Sethi ◽

Uttam Acharya ◽

Shashank Shekhar ◽

Barnik Saha Roy

Keyword(s):

Mechanical Properties ◽

Friction Stir Welding ◽

Joint Configuration ◽

Friction Stir ◽

Microstructure And Mechanical Properties ◽

Scarf Joint

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Effect of Stirring Pin Rotation Speed on Microstructure and Mechanical Properties of 2A14-T4 Alloy T-Joints Produced by Stationary Shoulder Friction Stir Welding

Materials ◽

10.3390/ma14081938 ◽

2021 ◽

Vol 14 (8) ◽

pp. 1938

Author(s):

Haifeng Yang ◽

Hongyun Zhao ◽

Xinxin Xu ◽

Li Zhou ◽

Huihui Zhao ◽

...

Keyword(s):

Mechanical Properties ◽

Friction Stir Welding ◽

Rotation Speed ◽

Weld Nugget ◽

Al Alloy ◽

Nugget Zone ◽

T Joints ◽

Friction Stir ◽

Stationary Shoulder ◽

Microstructure And Mechanical Properties

In this study, 2A14-T4 Al-alloy T-joints were prepared via stationary shoulder friction stir welding (SSFSW) technology where the stirring pin’s rotation speed was set as different values. In combination with the numerical simulation results, the macro-forming, microstructure, and mechanical properties of the joints under different welding conditions were analyzed. The results show that the thermal cycle curves in the SSFSW process are featured by a steep climb and slow decreasing variation trends. As the stirring pin’s rotation speed increased, the grooves on the weld surface became more obvious. The base and rib plates exhibit W- or N-shaped hardness distribution patterns. The hardness of the weld nugget zone (WNZ) was high but was lower than that of the base material. The second weld’s annealing effect contributed to the precipitation and coarsening of the precipitated phase in the first weld nugget zone (WNZ1). The hardness of the heat affect zone (HAZ) in the vicinity of the thermo-mechanically affected zone (TMAZ) dropped to the minimum. As the stirring pin's rotation speed increased, the tensile strengths of the base and rib plates first increased and then dropped. The base and rib plates exhibited ductile and brittle/ductile fracture patterns, respectively.

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