TWI Digital Library

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 feasibility of friction stir welding (FSW) for welding aluminium alloy 7020, used for the construction of light armoured fighting vehicles, was investigated and compared with MIG welding. Two joint configurations were tested: butt welding in 100…

A model which considers heat transfer to both tool and workpiece was developed to predict temperature distributions for the friction stir welding (FSW) process. The model assumes a cylindrical pin generating heat at the interface by friction, and th…

Different aluminium alloys were joined by friction stir welding (EN AW-5754-H14 to sheets of the same material, extruded profile EN AW-6063-T6 sheets to high pressure die cast EN AC-46000) and characterised by x-ray and microscopy studies, and the m…

The weldability of magnesium alloys by friction stir welding was studied using three die-cast alloys of thickness 6 mm (AM50 and AM60 Mg-Al-Mn alloys; AZ91 Mg-Al-Zn alloy) and one wrought alloy of thickness 6.4 mm (AZ231 Mg-Al-Zn alloy). Surface app…

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…

Experiments were conducted to compare heat input and weld hardness in friction stir welding (FSW) and MIG welding of aluminium alloy. Material A-6N01-T5 (Al, 0.8%Mg, 0.6%Si) of thickness 4 mm was used. The heat inputs were measured by calorimetry. H…

The Skew-Stir™ variant of friction stir welding (FSW), in which the axis of the tool is at an angle to that of the machine spindle, is described. The technique provides an improved path for metal to flow around the tool during welding, resulti…

Fatigue crack initiation and propagation was studied in friction stir welded aluminium alloy 7010-T7651 and also in the parent alloy, using a combination of theoretical and experimental techniques. Finite element analysis was used to model the stres…

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…

Aluminium alloy fusion welds were modified by friction stir processing (FSP) as a function of FSP location and tool design, and differences between the FSP locations and tools were quantified by microstructure and mechanical property measurements (u…

As part of a project to develop a physical-mathematical model and software for thermal simulation of the friction stir welding (FSW) process, an initial version "FricSim2.2" was created and verified, using the software tool "SpotFSW" to convert the …

The incorporation of strips of copper foil in friction stir welded aluminium alloy plate was evaluated for flow visualisation without disturbing the welding process. The strips, of 0.1 mm thickness, were placed in various longitudinal and transverse…

The design and construction of a prototype fixture and a corner fixture for making 90 degree corner joints in aluminium alloys by friction stir welding (FSW) are described. The requirements for a FSW weld fixture are outlined. The fixtures were test…

The microstructure of a friction stir weld (of unknown welding parameters) in titanium alloy (Ti, 6%Al, 4%V) is described. The microstructure was studied using optical microscopy, SEM and TEM. The features of the parent material, HAZ and the thermom…

Guidance notes devised for Lloyd's Register of Shipping surveyors for use in the quality assurance of friction stir welded aluminium alloys are presented.The notes cover: welding equipment, materials welded, and welding requirements (weld qualificat…