TWI Digital Library

Lap joints between 2 mm aluminium alloy sheet in 2024-T3 (Al, 4.4%Cu, 1.5%Mg, 0.6%Mn) and 7075-T6 (Al, 1.6%Cu, 2.5%Mg, 0.23%Cr, 5.6%Zn) were prepared and evaluated. The welds were produced using a range of welding and tool speeds, with a non-threade…

The mechanical properties of the parent metals and friction stir welded joints in aluminium alloy 6 mm plate 2014A, 7075 and 5083 are summarised. CTOD and J fracture toughness results are reported for the parent metal and up to five different region…

Friction stir welded joints in 2024-T351 Al-Cu-Mg alloy were subjected to fatigue testing to evaluate the suitability of this welding process for aircraft manufacture. Aluminium alloy (Al, 3.8-4.9%Cu, 1.2-1.8%Cu, 0.5%Si, 0.5%Fe, 0.2%Zr) of 6.35 mm (…

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…

Friction stir butt welding experiments were conducted on S45C medium carbon steel sheets (thickness 1.5 mm) under various conditions and the microstructure and mechanical properties of the welded joints were investigated. Single run butt welding was…

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…

The results of a programme to establish self reacting friction stir welding for thin gauge (less than 3 mm) aluminium alloy applications are reported divided into the five major phases: tool development; joint evaluation; strength optimisation; prot…

Modelling tools were developed to describe the relationships between process parameters, microstructural evolution and mechanical properties of the weld in friction stir welding (FSW). Experiments were conducted using aluminium alloy 6056. Initial t…

Work from two projects is described: "Qualistir" for the on-line quality control of friction stir welding in aluminium (by ultrasonic phased array examination of butt welded Al 7075); and a TWI feasibility study on inspection of Al 5083 butt and lap…

Computational fluid dynamics (CFD) methods were used to model the metal flow in the friction stir welding (FSW) process in order to optimise the pin profile to minimise the traversing force; welding experiments were carried out to validate the findi…

The influences of the thermal and mechanical stresses experienced during friction stir welding on the structure of coarse-grained aluminium alloy 2519-T87 were investigated. Plate of 25 mm thickness was welded at a speed of 1.5 mm/s, using a tool sp…

Friction stir welding (FSW) was investigated in aluminium alloys used in aircraft structures. Extruded shapes in alloys 2024 (Al, 4.96%Cu), 7475 (Al, 5.96%Zn, 2.57%Mg, 1.62%Cu) and 7050 (Al, 6.29%Zn, 2.36%Mg, 2.00%Cu) were welded; welds were evaluat…

A procedure has been developed for repairing welds made by friction stir welding (FSW) in cases where the tool breaks during welding. It involves the following stages: excavating the broken FSW tool, milling out a slot across the hole, machining an …

The quality of friction stir welds of butt joints (including the use of inserts to simulate compensation for poor fit up) between aluminium alloys 5083-H12 (Al, 4.6%Mg, 0.6%Mn, 0.3%Si) and 6082-T6 (Al, 0.7%Mg, 0.9%Si, 0.5%Mn), was evaluated. The wel…

The influence of friction stir welding on the microstructure and mechanical properties of aluminium alloy 6061 was investigated. Aluminium alloy 6061-T651 plate of 6.4 mm (0.25 in) thickness was friction stir welded and the joints characterised by o…

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…