Aluminum alloys

Friction stir welding

FSW of Aluminum with PP : Joining different parts is one of the crucial components of designing/engineering of materials. Presently, the current energy efficient low weight automotive and aerospace components consist of a different class of materials, such as metals, polymers, ceramics, etc. Joining these components remains a challenge. Here, we demonstrate metal (aluminum) and polymer (Polypropylene, pp) joining using mechanical friction. The detailed characterization clearly demonstrates that atomically locked interfaces are formed in such joining and no chemical bonds are formed during the joining.

Modeling and simulation

Modeling of Dissimilar FSW: A heat transfer numerical model is developed for friction stir welding of dissimilar materials Al 6061 and AZ31 alloy. Thermophysical properties were experimentally determined for the stir zone and compared with the base alloys. Experimentally determined thermo-physical properties of the stir zone are not strictly the average values of the base alloys but exhibit a complex relationship with the microstructural features and the intermixing of Al and Mg in the weld region.

Surface composites

Friction stir processing (FSP) is a suitable solid state processing route for surface composite preparation. Solid state processing route is superior in terms of compatibility and energy efficiency compared to conventional liquid state processing methods. The FSP, derived from the friction stir welding (FSW) process, is carried out at temperatures lower than the melting temperature of the base alloy. The surface composite preparation through FSP imparts minimal thermal effect on the processed material.

Friction stir channeling

The Friction stir channelling (FSC) process is based on the concept of transforming the void or tunnel defect originating in advancing side of Friction Stir process into continuous integral channel. The process was first invented and patented as manufacturing technique for heat exchanging devices and can have wide range application in compact heat exchanger industries. The important aspect for use of the channel in any thermal application is thermo-hydraulic performance. The geometrical parameters of channel (Shape, Cross Sectional Area, Surface Area, hydraulic diameter, Surface Roughness, and Length) decide the thermo-hydraulic performance of channel.

Heat treatment of alloys

Aluminum AA6082 extruded plates are solutionized at 520°C, 540°C, 580°C for 30 min. One set of samples were subjected to the natural aging heat treatment for 20 days, and 40 days other set samples were further subjected to artificial aging heat treatment where they are heated at 180°C for four hr to obtain the peak aging condition. Electrical conductivity is measured at different situations and correlated with the microstructural features and mechanical properties.

Load bearing capacity of tool pin during friction stir welding

Although friction stir welding (FSW) is now widely used for the welding of aluminum and other soft alloys, premature tool failure limits its application to hard alloys such as steels and titanium alloys. The tool pin, the weakest component of the …

Strains and strain rates during friction stir welding

Strains experienced by materials during friction stir welding (FSW) are important but scarce in the literature. Here we report the computed strains and strain rates during FSW of AA2524 from a three-dimensional coupled viscoplastic flow and heat …

Torque, power requirement and stir zone geometry in friction stir welding through modeling and experiments

The torque, power requirement and stir zone geometry during friction stir welding of AA2524 aluminum alloy were modeled by solving the equations of conservation of mass, momentum and energy. The model predictions agreed well with the corresponding …

Toward optimum friction stir welding tool shoulder diameter

Currently friction stir welding tools are designed by trial and error. Here we propose and test a criterion for the design of a tool shoulder diameter based on the principle of maximum utilization of supplied torque for traction. The optimum tool …