TWI Digital Library

An economic analysis was undertaken to compare the costs of onshore and offshore pipeline construction scenarios for welds made using friction stir welding (FSW) and conventional mechanised MIG/MAG welding. Pipe diameters of 1067 and 305 mm were sel…

Models to predict the precipitate and grain size evolution in AA7449 aluminium alloy friction stir welds are presented and compared with experimental data. Bead on plate welds on 3.2 mm thickness sheets of composition Al, 8.4%Zn, 2.1%Mg, 1.8%Cu were…

With regard to the occurrence of residual oxide defects associated with friction stir welding (FSW) of aluminium alloys, an investigation is presented into a possible alternative mechanism for oxide formation within the weld nugget involving enhance…

The feasibility of friction stir welding TIMETAL 21S beta titanium in the annealed condition was investigated. The composition of the alloy is Ti, 14-16%Mo, 2.4-3.2%Nb, 2.5-3.5%Al, 0.15-0.25%Si, max.0.4%Fe, 0.11-0.17%O, max.0.05%C, max.0.05%N, max.0…

The microstructure of joints produced between dissimilar Al alloys by friction stir welding (FSW) was studied. FSW was performed for joining of 5083/6061 Al alloy workpieces of 5 mm thickness using a rotation speed of 1800 rpm and a welding speed of…

In order to develop a method for microjoining by friction stir welding (FSW), micro-FSW trials were conducted on Mg alloy AZ31 (2.97%Al, 0.83%Zn) thin sheets (0.4 mm thickness), and the welding performance was assessed. The micro-FSW system incorpor…

Three recently published finite element studies, modelling friction stir welding (FSW) of different aluminium alloys, were reproduced using ABAQUS software and the results were comparatively assessed. The models considered were as follows: heat tran…

A three-dimensional thermomechanical model of the friction stir welding of aluminium alloy was developed, based on the finite element method, to predict temperature and stress distributions in the workpiece, residual stresses, and the stresses exper…

The design of a polycrystalline cubic boron nitride friction stir welding tool, tool holder and machine for use with high melting temperature materials is described. A polycrystalline cubic boron nitride truncated cone tool tip, capable of working a…

Friction stir welds were made in 4 mm thick sheets of aluminium alloys 2024-T3 and 6013-T6. The stress intensity factor due to residual stresses was determined using the cut compliance method. The residual stress distribution was calculated using th…

Microstructural examination and a root bend test were used to examine the results of friction stir welding in dissimilar welds of aluminium alloys A-5083 (Al, 4.5%Mg) and A-6N01 (Al, 0.6%Mg, 0.65%Si) of thickness 4 mm. Optimum welding parameters (to…

The tensile and bend properties of friction stir welded butt joints in aluminium alloys 2024-T3, 6013-T6 and 7475-T76 were determined, including welds in 2024 and 7475 subjected to PWHT. The ultimate tensile strength, proof stress at 0.2% strain, an…

The non-destructive testing (NDT) aspects of the Qualistir project for the on-line quality control of friction stir welding in aluminium are described. Definitions are given for the following defects: voids, wormholes, lack of penetration, faying su…

The development of three-dimensional column-type friction stir welding (FSW) equipment for robotic FSW of joints with complex shapes is described. The process requires a large force and precision control for tool penetration. The specification of th…

The influence of pores and residual stresses on fatigue crack propagation was studied for friction stir welded joints in aluminium alloys 2024-T3 and 6013-T6 of thickness 4 mm. Good welds and pore-containing welds were produced using tools with and …

The relationship between microstructure and properties, and the influence of microstructure on the fracture toughness of friction stir welded aluminium alloys with weld zone strength undermatching were investigated. Welds were made in 5005-H14, 2024…

The fine scale precipitation in the nugget zone and in the HAZ of a weld in aluminium alloy AA-6082 (Al, 0.7%Mg, 0.5%Mn, 0.9%Si) of thickness 5-10 mm made by friction stir welding (FSW) was examined using transmission electron microscopy. The dissol…

An investigation was undertaken to determine the strength and fracture toughness of joints fabricated by friction stir welding (FSW) in commercial X65 (0.07%C, 1.56%Mn, 0.06%Nb, 0.013%Ti) and X80 (0.05%C, 1.52%Mn, 0.26%Cr, 0.26%Cu, 0.1%Nb and 0.07%C…

Local stress-strain curves were determined from an array of spherical indents on the cross-section of the joint of a friction stir welded (FSW) high strength aluminium alloy AA 2198 sheet, in order to characterise the mechanical properties of differ…

An algorithm and procedure for controlling process zone temperature during friction stir processing are presented. The approach is based on the correlation between weld zone temperature with spindle power. A simplified thermal balance model of the w…