TWI Digital Library

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…

Dissimilar lap joints between AlSi10MgMn aluminium alloy sheets (thickness 3 mm) and Al-Si coated Usibor 1500 22MnB5 hot stamped boron steel sheets (thickness 1.8 mm) were fabricated by friction stir spot welding (FSSW) under different processing co…

A review is presented of process development work undertaken with regard to a machine concept assessment and the realisation of a fully 3D-capable 5-axis parallel kinematic friction stir welding machine, a so-called pentapod, suitable for large and …

Butt welding experiments were undertaken to investigate the feasibility of joining a metal matrix composite (MMC), comprising an Al-10%Si matrix and 20 vol.% SiC particles, to an AA-6063-T5 alloy by friction stir welding (FSW). Optimum process param…

An experimental investigation is presented into the precipitation and hardening mechanism during FSW (friction stir welding) of Ni model alloys (Ni, 20%Cr, 2%Al, 2%Ti and Ni, 20%Cr, 3%Al, 3%Ti) in which Al and Ti contents were varied to control the …

Friction stir spot welding experiments were conducted on dissimilar metal joints between AA5052 aluminium alloy and three kinds of zinc coated steel, and weldability analysis, microstructure observations and mechanical tests were undertaken. The coa…

Friction stir processing (FSP) experiments were undertaken to modify the microstructure of Ti-6%Al-4%V parent metal specimens, in both alpha/beta and beta processed conditions, and TIG weld overlays deposited onto Ti, 6%Al, 4%V alloy using matching …

A 3D thermomechanical model, incorporating knowledge of residual distortion and stress, was developed as a finite element tool for simulation and optimisation of clamping situations in friction stir welding (FSW) and experiments were undertaken on A…

Similar and dissimilar joints between 2014-T6 (Al, 4.67%Cu) and 6061-T6 (Al, 0.9%Mg, 0.63%Si) aluminium alloys were fabricated by friction stir welding (FSW) with various sets of process parameters, and the microstructure and mechanical properties o…

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 …