Phase-field modelling of dynamic recrystallization process during friction stir welding of aluminium alloys

The grain refinement mechanisms along the material flow path in pure and high-purity Al were examined, using the marker insert and tool stop action methods, during the rapid cooling friction stir welding using liquid CO2. In pure Al subjected to a low welding temperature of 0.56Tm (Tm: melting point), the resultant microstructure consisted of a mixture of equiaxed and elongated grains, including the subgrains. Discontinuous dynamic recrystallization (DDRX), continuous dynamic recrystallization (CDRX), and geometric dynamic recrystallization are the potential mechanisms of grain refinement. Increasing the welding temperature and Al purity encouraged dynamic recovery, including dislocation annihilation and rearrangement into subgrains, leading to the acceleration of CDRX and inhibition of DDRX. Both C- and B/-type shear textures were developed in microstructures consisting of equiaxed and elongated grains. In addition, DDRX via high-angle boundary bulging resulted in the development of the 45° rotated cube texture. The B/ shear texture was strengthened for the fine microstructure, where equiaxed recrystallized grains were fully developed through CDRX. In these cases, the texture is closely related to grain structure development.

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Optimization of friction stir welding parameters during joining of AA3103 and AA7075 aluminium alloys using Taguchi method

Materials Today Proceedings ◽

10.1016/j.matpr.2021.02.246 ◽

2021 ◽

Author(s):

Anil Raj ◽

J. Pratap Kumar ◽

Anil Melwin Rego ◽

Ivan Sunit Rout

Keyword(s):

Friction Stir Welding ◽

Taguchi Method ◽

Aluminium Alloys ◽

Welding Parameters ◽

Friction Stir

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Optimization of friction stir welding parameters of dissimilar aluminium alloys 6061 and 5083 by using response surface methodology

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211005804 ◽

2021 ◽

pp. 095440622110058

Author(s):

Sanjeev Verma ◽

Vinod Kumar

Keyword(s):

Tensile Strength ◽

Friction Stir Welding ◽

Tilt Angle ◽

Feed Rate ◽

Aluminium Alloys ◽

Welded Joint ◽

Welding Parameters ◽

Friction Stir ◽

Industrial Sectors ◽

Tool Pin

Aluminium and its alloys are lightweight, corrosion-resistant, affordable and high-strength material and find wide applications in shipbuilding, automotive, constructions, aerospace and other industrial sectors. In applications like aerospace, marine and automotive industries, there is a need to join components made of different aluminium alloys, viz. AA6061 and AA5083. In this study friction stir welding (FSW) is used to join dissimilar plates made of AA6061-T6 and AA5083-O. The effect of varying tool pin profile, tool rotation speed, tool feed rate and tilt angle of the tool has been investigated on the tensile strength and percentage elongation of the welded joints. Box-Behkan design, with four input parameters and three levels of each parameter has been employed to decide the set of experimental runs. The regression models have been developed to investigate the influence of welding variables on the tensile strength and elongation of the welded joint. It is revealed that with the increase in welding parameters like tool rpm, tool feed rate and tilt angle of the tool, both the mechanical properties increase, reach a maximum level, followed by a decrease with further increase in the value of parameters. Amongst different types of tool pin profiles used, the FSW tool having straight cylindrical (SC) pin profile is found to yield the maximum strength and elongation of the welded joint for different combinations of welding parameters. Multiple response optimization indicates that the maximum UTS (135.83 MPa) and TE (4.35%) are obtained for the welded joint fabricated using FSW tool having SC pin profile, tilted at 1.11° and operating at tool speed and feed rate of 1568 rpm and 39.53 mm/min., respectively.

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Friction Stir Welding of Dissimilar Formed Mg Alloys (AZ31/AZ91)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.486-487.249 ◽

2005 ◽

Vol 486-487 ◽

pp. 249-252 ◽

Cited By ~ 3

Author(s):

Chang Yong Lee ◽

Won Bae Lee ◽

Yun Mo Yeon ◽

Seung Boo Jung

Keyword(s):

Friction Stir Welding ◽

Dynamic Recrystallization ◽

Tensile Test ◽

Intermetallic Compounds ◽

Grain Growth ◽

Weld Zone ◽

Mg Alloys ◽

Mg Alloy ◽

Friction Stir ◽

Az31 Mg Alloy

Friction stir welding of dissimilar formed Mg alloys(AZ31/AZ91) was successfully carried out at the limited welding conditions. In a sound joint, SZ was mainly consisted of AZ31 Mg alloy which was located the retreating side. Dynamic recrystallization and grain growth occurred and β intermetallic compounds of AZ 91 Mg alloy was not observed in SZ. BM had a higher hardness than that of the weld zone. The fracture location was not weld zone but BM of the AZ91 Mg alloy in tensile test.

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