Influence of process parameters on friction stir spot welded aluminum joints by various threaded tools

Friction Stir Welding (FSW) is an innovative solid-state joining process, which is gaining a great deal of attention in several applicative sectors. The opportune definition of process parameters, i.e. minimizing residual stresses, is crucial to improve joint reliability in terms of static and dynamic performance. Longitudinal residual stresses, induced by FSW in AA2024-T3 butt joints, have been inferred by means of a recently developed technique, namely the contour method. Two approaches to stress measurement have been adopted; the former is based on the assumption of uniform material properties, the latter takes into account microstructural effects and material properties variations in the welding zones. The influence of process parameters, namely rotating and welding speeds, on stress distribution is also discussed.

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Microstructural, Thermal and Corrosion Characterization of Friction Stir Welded Magnesium Alloys

International Journal of Vehicle Structures and Systems ◽

10.4273/ijvss.13.4.01 ◽

2021 ◽

Vol 13 (4) ◽

Author(s):

M.A. Unnikrishnan ◽

J. Edwin Raja Dhas

Keyword(s):

Magnesium Alloys ◽

Process Parameters ◽

Salt Spray ◽

Sem Analysis ◽

Maximum Efficiency ◽

Primary Analysis ◽

Influence Of Process Parameters ◽

Friction Stir ◽

Weld Properties ◽

Dta Analysis

The requirement for structural materials with demanding properties is always a major concern among automotive researchers. Magnesium alloys possess the required properties. In this work magnesium alloys, AZ31B and AZ91B were joined by friction stir welding. The influence of process parameters on the weld properties has been studied. The process parameters were tool rotational speed, welding speed, tilt angle. Three different combinations AZ31B-AZ91B, AZ31B-AZ31B and AZ91B-AZ91B were friction stir welded. Non-destructive tests have been performed on the welded joints as the primary analysis. After mechanical testing, optical microscopic examination comprising of macrostructure analysis, microstructure analysis and SEM analysis were carried out on selected specimens and the results are formulated. The corrosion behavior of Mg alloys has been tested using a salt spray test. The thermal behavior was studied using thermogravimetric and differential thermal analysis. The joints were friction stir welded with maximum efficiency where grain refinement was observed in the weld microstructure of dissimilar alloys and the elongated grains was recrystallized. This paper primarily focuses on the microstructural aspects, corrosion performances and TG/DTA analysis.

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Fabrication and characterization of friction stir processed Al 6061 reinforced with TiB2-Al2O3

International Journal of Structural Integrity ◽

10.1108/ijsi-03-2020-0026 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Ch. Mohana Rao ◽

K. Mallikarjuna Rao

Keyword(s):

Mechanical Properties ◽

Aluminum Alloy ◽

Process Parameters ◽

Friction Stir Processing ◽

Practical Implication ◽

Research Work ◽

Influence Of Process Parameters ◽

Volume Percentage ◽

Content Type ◽

Friction Stir

PurposeThe objective of the paper is to evaluate the fabrication process and to study the influence of process parameters of friction stir processing of 6061-TiB2-Al2O3 Aluminum alloy surface composite on microhardness tensile strength, and microstructure.Design/methodology/approachFriction stir processing method is used for attaining the desired mechanical properties, and selectively processed reinforcements to fabricate the samples. The Taguchi technique was used to optimize rotational speed, travel speed and volume percentage of reinforcement particles to enhance the mechanical properties of 6061-TiB2-Al2O3 Aluminum alloy composite.FindingsThe fabrication of surface composites through FSP allows new inventions in terms of material with enhanced surface layers without changing the base metal.Practical implicationsTo examine the behavior of the surface of the composites in the different zones, the practical implication consists of the use of different characterization techniques like optical microscopy and scanning microscopy for microstructural behavior and the measurement of hardness and tensile tests for mechanical behavior.Originality/valueThe research work consists of tool design and process parameters, which can affect the final product (microstructural changes), and the performance of the modified surface layer behavior was studied and presented.

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