Influence of welding parameters and tool geometry on the morphology and mechanical performance of ABS friction stir spot welds

Friction stir welding is a solid-state welding method that produces joints with superior mechanical and metallurgical properties. However, the negative effects of the thermal cycle during welding dent the mechanical performance of the weld joint. Hence, in this research study, the joining of aluminum tailor welded blanks by friction stir welding is carried out in underwater conditions by varying the welding parameters. The tensile tests revealed that the underwater welded samples showed better results when compared to the air welded samples. Maximum tensile strength of 229.83 MPa was obtained at 1000 rpm, 36 mm/min. The improved tensile strength of the underwater welded samples was credited to the suppression of the precipitation of the secondary precipitates due to the cooling action provided by the water. The lowest hardness of 72 HV was obtained at the edge of the stir zone which indicated the weakest region in the weld zone.

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The Influence of Tool Wear on the Mechanical Performance of AA6061-T6 Refill Friction Stir Spot Welds

Materials ◽

10.3390/ma14237252 ◽

2021 ◽

Vol 14 (23) ◽

pp. 7252

Author(s):

Willian S. de Carvalho ◽

Maura C. Vioreanu ◽

Maxime R. A. Lutz ◽

Gonçalo P. Cipriano ◽

Sergio T. Amancio-Filho

Keyword(s):

Tool Wear ◽

Mechanical Performance ◽

Welding Parameters ◽

Fracture Mechanisms ◽

Friction Stir ◽

Lap Shear ◽

Tool Wear Mechanisms ◽

Local Mechanical Property ◽

Property Changes ◽

Aluminum And Magnesium Alloys

The Refill Friction Stir Spot Welding (RFSSW) process—an alternative solid-state joining technology—has gained momentum in the last decade for the welding of aluminum and magnesium alloys. Previous studies have addressed the influence of the RFSSW process on the microstructural and mechanical properties of the AA6061-T6 alloy. However, there is a lack of knowledge on how the tool wear influences the welding mechanical behavior for this alloy. The present work intended to evaluate and understand the influence of RFSSW tool wear on the mechanical performance of AA6061-T6 welds. Firstly, the welding parameters were optimized through the Designing of Experiments (DoE), to maximize the obtained ultimate lap shear force (ULSF) response. Following the statistical analysis, an optimized condition was found that reached a ULSF of 8.45 ± 0.08 kN. Secondly, the optimized set of welding parameters were applied to evaluate the wear undergone by the tool. The loss of worn-out material was systematically investigated by digital microscopy and the assessment of tool weight loss. Tool-wear-related microstructural and local mechanical property changes were assessed and compared with the yielded ULSF, and showed a correlation. Further investigations demonstrated the influence of tool wear on the height of the hook, which was located at the interface between the welded plates and, consequently, its effects on the observed fracture mechanisms and ULSF. These results support the understanding of tool wear mechanisms and helped to evaluate the tool lifespan for the selected commercial RFSSW tool which is used for aluminum alloys.

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Effect of Tool Geometry and Process Parameters on Microstructure and Mechanical Properties of Friction Stir Spot Welded 2024-T3 Aluminum Alloy Sheets

10.20944/preprints201612.0108.v1 ◽

2016 ◽

Author(s):

Memduh Murtulmuş

Keyword(s):

Aluminum Alloy ◽

Penetration Depth ◽

Rotational Speed ◽

Stir Zone ◽

Weld Strength ◽

Tool Geometry ◽

Welding Parameters ◽

Tensile Shear ◽

Shear Tests ◽

Friction Stir

Aluminum alloy Al 2024-T3 were successfully joined using friction stir spot jwelding joining (FSSW). Satisfactory joint strengths were obtained at different welding parameters (tool rotational speed, tool plunge depth, dwell time) and tool pin profile (straight cylindrical, triangular and tapered cylindrical). Resulting joints were welded with welded zone. The different tools significantly influenced the evolution on the stir zone in the welds. Lap-shear tests were carried out to find the weld strength. Weld cross section appearance observations were also done. The macrostructure shows that the welding parameters have a determinant effect on the weld strength (x: the nugget thickness, y: the thickness of the upper sheet and SZ: stir zone). The main fracture mode was pull out fracture modes in the tensile shear test of joints. The results of tensile shear tests showed that the tensile-shear load increased with increasing rotational speed in the shoulder penetration depth of 0.2 mm. Failure joints were obrerved in the weld high shoulder penetration depth and insufficient tool rotation.

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Effect of Tool Geometry and Welding Parameters on Friction Stir Welded Lap Joint Formation with AA2099-T83 and AA2060-T8E30 Aluminium Alloys

Metals ◽

10.3390/met10070872 ◽

2020 ◽

Vol 10 (7) ◽

pp. 872 ◽

Cited By ~ 1

Author(s):

Egoitz Aldanondo ◽

Javier Vivas ◽

Pedro Álvarez ◽

Iñaki Hurtado

Keyword(s):

Aluminium Alloys ◽

Defect Formation ◽

Lap Joints ◽

Tool Geometry ◽

Welding Parameters ◽

Lap Joint ◽

Friction Stir ◽

Reaction Forces ◽

Cold Lap ◽

Probe Geometry

In this paper the effect of tool geometry and welding parameters on friction stir welded lap joints with AA2099-T83 and AA2060-T8E30 aluminium alloys has been investigated through the study of the material flow and weld formation along with the reaction forces during friction stir welding (FSW) for various sets of welding parameters and two FSW tools with different geometrical features. The results showed that welding parameters and tool probe geometry strongly affect the characteristics of the typical defect features (hook and cold lap defects) of the friction stir welded lap joints. From the relationship established between the welding parameters, tool probe geometry and the hook and cold lap defect formation, some guidelines are concluded with the objective of guaranteeing appropriate FSW lap joint properties.

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Influences of welding parameters on mechanical properties of AZ31 friction stir spot welds

Science and Technology of Welding & Joining ◽

10.1179/1362171812y.0000000008 ◽

2012 ◽

Vol 17 (4) ◽

pp. 304-308 ◽

Cited By ~ 2

Author(s):

N Sun ◽

T H North ◽

D R Chen ◽

Y H Yin

Keyword(s):

Mechanical Properties ◽

Welding Parameters ◽

Spot Welds ◽

Friction Stir

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Friction Stir Spot Welds between Aluminium and Steel Automotive Sheets: Influence of Welding Parameters on Mechanical Properties and Microstructure

Welding in the World ◽

10.1007/bf03266697 ◽

2009 ◽

Vol 53 (1-2) ◽

pp. R13-R23 ◽

Cited By ~ 34

Author(s):

Gunter Figner ◽

Rudolf Vallant ◽

Thomas Weinberger ◽

Norbert Enzinger ◽

Hartmuth Schröttner ◽

...

Keyword(s):

Mechanical Properties ◽

Welding Parameters ◽

Spot Welds ◽

Friction Stir

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Effect of Tool Parameters on Mechanical Properties of Friction Stir Welded Aluminum Alloy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.786.111 ◽

2015 ◽

Vol 786 ◽

pp. 111-115 ◽

Cited By ~ 1

Author(s):

Srinivasa Rao Pedapati ◽

G. Vimalan ◽

Mokhtar Awang ◽

A.M.A. Rani

Keyword(s):

Mechanical Properties ◽

Rotational Speed ◽

Base Material ◽

Hardness Test ◽

Tensile Tests ◽

Tool Geometry ◽

Welding Parameters ◽

Material Strength ◽

Friction Stir ◽

Tool Profiles

The mechanical properties of weld joints in Friction Stir Welding (FSW) are influenced by the welding parameters such as rotational speed, tool geometry and welding speed. In the present study, three different tool profiles have been used to weld the joints with three different rotational speed and two welding speeds. Full factorial experiments have been conducted using DoE. The mechanical properties of weld joint were evaluated by means of tensile tests and hardness test at room temperature. The experiment result shows that the average highest number of hardness was 40.06 HRB with square tool at a rotational speed of 2000rpm while lowest hardness was 30.84 HRB with cylindrical threaded tool at rotational speed of 1800rpm. The maximum tensile strength of the joint obtained is 265 M Pa which is close to base material strength. It is observed from experimental results that joints made by square tool yield more strength compared to other tool profiles.

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