TWI

A friction stir welding technology was developed to facilitate welding extruded profiles together as a whole side wall in an aluminium railway wagon for coal transportation. The material employed was an AA 6061-T6 alloy plate (thickness 7 mm). Some …

An investigation is presented into tool material development of large polycrystalline cubic BN blanks to facilitate friction stir welding of thick section steel specimens (thickness 9.5 or 20 mm). Tool materials were produced from 90% polycrystallin…

An apparatus was developed to analyse the contact condition between the rotating tool and the workpiece during friction stir welding, and empirical tests were performed to determine the friction conditions (static, dynamic and the transition from on…

An investigation is presented into the effect of a paint bake cycle on the performance of friction stir spot welded (FSSW) joints fabricated in heat-treatable 6111-T4 aluminium alloy automotive sheets (thickness 0.93 mm) using a pinless tool and sho…

Friction stir lap diffusion welding was employed to fabricate dissimilar AA 6060 aluminium alloy/mild steel joints and mechanical testing and metallurgical examination of the weldments were undertaken to investigate the effect of microstructure form…

Finite element models of the friction stir welding of aluminium alloys are reviewed and the results compared with experimental measurements. Contact between the pin and the workpiece is considered in two ways: frictional contact; or assuming the mat…

The use of friction stir welding, as an alternative to bolted or riveted joints, for the assembly of Airbus wings is discussed. Issues considered include: cost reduction, weight reduction, joint quality, and enhanced in-service performance. Potentia…

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…

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…

A review is presented of the progressive emergence of conceptual tools associated with friction stir welding (FSW) at the Marshall Space Flight Center, USA, from the discovery of the shear surface, wiping metal transfer and the invention of a kinema…

With regard to the production of aluminium alloy T joints for stiffened panel construction by friction stir welding (FSW), an investigation is presented into the fabrication of FSW T joints with AA 6082-T6 alloys and the influence of welding paramet…

Tapered probe and parallel probe tools were employed in friction stir welding of thick section AA 6082-T6 aluminium alloy specimens (thickness 38 mm) and the effect of tool geometry on weldment microstructure and crystallographic texture was investi…

Friction stir welding (FSW) experiments were undertaken on commercially pure Ti and Ti-6%Al-4%V plates (thickness 6 mm) by incorporating nickel foil markers of varying thicknesses to reduce forging load, enhance surface finish, eliminate void format…

A thermal model with a thermo pseudo mechanical (TPM) heat source was employed to investigate the influence of process parameters (rotational speed, feed rate and tool geometry) on the temperature profile at the interface of dissimilar metal lap joi…

A kinematic approach is presented for modelling the friction stir welding process and the relationship between tool geometry and process parameters. The model was used to describe the correlation between features of the weld nugget, process paramete…

The material flows of aluminium and steel during friction stir welding were visualised in three dimensions using x-ray transmission radiographic real-time imaging. The movement of a miniature spherical tungsten tracer during welding was visualised u…

5083-O aluminium alloy sheets (thickness 3 mm) were butt welded using a gate-type friction stir welding (FSW) machine to investigate tolerance to deviations in butt-line/tool-travel line, gap spacing and tool roll angle, and the welded joints were e…

The origin of the lines of micrometre sized oxide particles observed in aluminium alloy friction stir welds was investigated. Butt and bead on plate welds were prepared using 6 mm plate of aluminium (99.999%Al and 99.5%Al) and aluminium alloy 6056 (…

Friction stir welding (FSW) was carried out on AZ31 magnesium alloy (Mg, 3%Al, 1%Zn) plates of thickness 6 mm in order to examine the relationship between weld microtexture and tensile properties. Orientation imaging microscopy was used to examine m…

Thermomechanical and microstructural modelling were performed for the friction stir welding process, simulating the thermal diffusion during and after welding (in the cooling stage), and comparing the results with experimental data obtained for fric…