Microstructure and mechanical behaviour of friction-stir-welded magnesium alloys: As-Welded and post weld heat treated

2019 ◽  
Vol 20 ◽  
pp. 100600
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Magnesium Alloys ◽  
Mechanical Behaviour ◽  
Friction Stir ◽  
Heat Treated ◽  
Weld Heat

An investigation on microstructure and mechanical properties of post-weld heat-treated friction stir welds in aluminum alloy 2024-W

2012 ◽  
Vol 227 (4) ◽  
pp. 649-662 ◽  
Author(s):  
Hakan Aydın ◽  
Ali Bayram ◽  
İsmail Durgun
Keyword(s):  
Room Temperature ◽  
Welded Joint ◽  
Solution Treatment ◽  
Heat Treatments ◽  
Maximum Hardness ◽  
Friction Stir ◽  
Base Materials ◽  
Heat Treated ◽  
Aluminum Alloy 2024 ◽  
Weld Heat

The present work describes the results obtained from microstructural and mechanical evaluation of post-weld heat treated friction stir welds of 2024 aluminum alloys in the W temper state. Post-weld heat treatments have been carried out at 510 °C for 2.5 h followed by ageing at room temperature for 6 months, at 100 °C and 190 °C for 10 h, and by cooling in static air (O-temper). The solution treatment caused abnormal coarsening of the grains in the stir zone, which resulted in a drop in microhardness. The strength of the as-welded joint was significantly incrased by post weld heat treatments. The maximum hardness and strength values were obtained in T6 (190 °C, 10 h) treated joint. However, the T6 (190 °C, 10 h) treated joint had the lowest ductility. On the other hand, the tensile properties of the post-weld heat treated joints were far lower than those of the unwelded base materials in the same temper states. In addition, the post-weld heat treatments did not significantly change the fracture locations of the friction stir welds.

Effect of post weld heat treatment and welding parameters on mechanical and corrosion characteristics of friction stir welded aluminium alloy AA2014-T6

2019 ◽  
Vol 43 (2) ◽  
pp. 230-236
Author(s):  
Ashok S. Kannusamy ◽  
Ravindran Ramasamy
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Welding Process ◽  
Post Weld Heat Treatment ◽  
Welding Parameters ◽  
Friction Stir ◽  
Heat Treated ◽  
Ageing Period ◽  
Weld Heat

This paper addresses the effect of post weld heat treatment methods on the mechanical and corrosion characteristics of friction stir welded aluminum alloy AA2014-T6. Aluminum alloy AA2014 is mainly used in applications that demand high strength to weight ratios, such as aerospace, marine, and industrial applications. In this work, AA2014-T6 plates of 6 mm thick were butt welded using a tool with a square profile. Tensile strength, hardness, and corrosion characteristics were compared between the samples as welded and post weld heat treated. Welded samples that were heat treated for a shorter ageing period (8 h) showed improved tensile strength irrespective of welding process parameters, compared to as-welded samples. The samples heat treated for a longer ageing period (9 h) showed a decline in tensile strength for low tool rotation speed. Hardness increased in welded samples heat treated for 8 h. Welded samples heat treated for 9 h show high passivity in corrosion media.

Strength and hardness of post-weld heat-treated thick section 7075 Al alloy friction stir welds

2019 ◽  
Vol 61 (5) ◽  
pp. 411-416 ◽  
Author(s):  
Thadivaka Ramakrishna ◽  
Silaparasetti Srinivasa Rao ◽  
Gurugubelli Swami Naidu
Keyword(s):  
Al Alloy ◽  
Thick Section ◽  
Friction Stir ◽  
7075 Al Alloy ◽  
Heat Treated ◽  
Weld Heat

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

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