TWI

A computational fluid dynamics code ("CosmosFlow") was employed to evaluate the temperature distribution in materials during friction stir welding (FSW). Thermal simulations based on finite element models were undertaken to predict the optimum ratio…

Friction stir spot welding (FSSW) was performed on dual phase 800 high strength automotive steel (0.14%C, 0.23%Si, 1.52%Mn) to establish the effect of tool rotation speed (750-2400 rpm) for a number of weld cycles featuring different Z-axis plunge r…

Defect free welded joints were fabricated in 5083-O aluminium alloy (Al, 4.3%Mg, 0.65%Mn) plates (thickness 20 mm) by friction stir welding (FSW) and the influence of tool geometrical features on their microstructures and structure properties relati…

Controlled force monitored plug-in tests were undertaken to investigate the influence of rotational speed and to analyse flow regimes during friction stir welding (FSW) of different aluminium alloys. Experimental specimens comprised sheets (thicknes…

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 …

An investigation was undertaken to examine the interactions, required process adjustments and resultant joint properties associated with conventional and robotic stationary shoulder friction stir welding (SSFSW) for scaled tool geometries. In order …

The microstructure, hardness, tensile strength and fracture toughness of friction stir welds in cryogenic tanks made from standard AA2219 AlCu alloy and advanced AA2195 AlCuLi alloy (5 mm thickness) were investigated. AA2195 has relatively low densi…

Modified Gleeble hot torsion testing was used to simulate four microstructure regions in HSLA-65 steel (0.07%C, 0.24%Si, 1.5%Mn, 0.14%Cr, 0.34%Ni, 0.25%Cu, 0.06%Mo) joints fabricated by friction stir welding (FSW) and the results were verified by op…

Fatigue crack growth in friction stir welded (FSW) aluminium alloys 2024-T3 and 6013-T6 were predicted using two commercial software programs, ESACRACK and AFGROW in order to facilitate lifetime predictions of FSW aircraft structures. The following …

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…

In relation to the application of tailor welded blanks of aluminium alloys to the vehicle weight reduction process, an investigation is presented into the precipitation sequence in friction stir welded 6016 alloy sheets (thickness 2 mm) during a pai…

Friction stir welding (FSW) studies were undertaken to join sheet and plate specimens of aluminium alloys in a butt joint configuration, and design of experiments methods were employed to optimise process parameters with respect to weldment quality …

The influence of weld length on pin breakage during friction stir welding (FSW) of aluminium alloy was investigated. Tool geometry, microstructure, pin diameter and the occurrence of cracking were studied during welding. Welded joints were made in 7…

A review is presented of the development of W, 25%Re friction stir welding (FSW) tool materials for application to steels and hard metals, such as titanium and nickel-based superalloys. Issues discussed include: the DUST (dual use science and techno…

Numerical modelling and experimental measurements were undertaken to investigate the extension and microstructure of the HAZ during friction stir welding (FSW) of 7075 aluminium alloy (Al, 5.86%Zn, 2.37%Mg, 1.91%Cu) thin sheets (thickness 1.2 mm). W…

Process force and discontinuity models were derived to estimate the forces observed in friction stir welding (FSW) in order to develop a method of detecting discontinuities during FSW using physics-based process modelling. FSW welded joints with and…

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…

With regard to the need to control process temperature in friction stir welding to enhance process stability and weldment mechanical properties, a feedforward feedback control system was designed based on two nonlinear single input single output (SI…

An investigation is presented into pore formation and grain growth in aluminium alloys during TIG welding after friction stir welding (FSW), for reasons of repair or fabrication, and into two methods to suppress these problems. The material studied …

The design, fabrication and evaluation of a portable friction stir welding (FSW) system for the in-situ field repair of aluminium structures to a depth of 6 mm is reported. The conceptual design of the FSW machine was produced using a dual-track app…