TWI

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…

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…

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…

An analysis procedure was developed to relate the geometry and microstructure of lap configuration friction spot welds to the joints' mechanical behaviour. Using 2 mm thickness aluminium alloy AA 2024-T3 sheet as the basis for simulation, a three-di…

An integrated multi-physics model was employed to predict the temperature distribution, the post-weld grain size distribution and the local subgrain size distribution around the pin during friction stir welding (FSW) of 6061 aluminium alloys. The mu…

The Taguchi method was employed to determine optimum process parameters for friction stir welding of dissimilar joints between AA 6061 (Al, 0.84%Mg, 0.54%Si, 0.4%Fe, 0.24%Cu) and AA 7075 (Al, 5.58%Zn, 2.28%Mg, 1.6%Cu) aluminium alloys. Welding was p…

A modified friction stir lap welding process was developed to encase uranium alloy foil in an aluminium jacket and results were compared with two other bonding methods for fabricating monolithic fuel plates, namely hot isostatic pressing and transie…

The plastic flow and microstructure of friction stir welded butt joints in aluminium alloy 7050-T7451 (Al, 6.2%Zn, 2.2%Mg, 2.3%Cu, 0.01%Zr) of thickness 7 mm were investigated. Cylindrical compression test samples (5.1 mm diameter and height) machin…

A discussion is presented on developments in polycrystalline cubic boron nitride (PCBN) tool design for use in the friction stir welding of high temperature materials such as steels. Improvements in tool material grades, tool design and FSW equipmen…

The effects of rotation speed, welding speed and Z-axis force on process response variables (power, specific energy, torque, X-axis force) and properties (nugget hardness, strength and ductility, nugget grain size and HAZ hardness) of AA2524-T351 fr…

High alloy tool steel H13, silicon nitride(Si3N4) and tungsten carbide (WC) bonded with 10%Co cylindrical pin tools (12.5 mm diameter) were evaluated for the friction stir welding of aluminium alloy 6061 containing 20 wt% alumina by determining an e…

Experimental measurements and finite element modelling were undertaken to investigate the deposition of AA1050 commercially pure aluminium layers on AA 2024-T351 aluminium alloy substrates by friction surface cladding (FSC). Experiments were perform…

A round robin investigation was made to determine if defects found using the non-destructive evaluation (NDE) techniques of ultrasonic phased array and x-ray inspection, can be identified by a real-time, feedback-based friction stir weld analysis to…

An investigation is presented into the fabrication of welded joints in high strength aluminium alloys by friction stir welding (FSW) and into the application of the technology for manufacturing lightweight aircraft structures. The materials consider…

Experimental measurements and finite element modelling were undertaken to investigate the deposition of AA1050 commercially pure aluminium layers on AA 2024-T351 aluminium alloy substrates by friction surface cladding (FSC). Experiments were perform…

The results of two testing programmes dealing with the metallurgical and mechanical properties of friction stir weldments (thickness 6 and 25 mm) in the aluminium alloys 2024, 5083, 6082/6060 and 7075 are reported, and a systematic study of the key …