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A major barrier, preventing RFSSW from use by manufacturers, is the long cycle time that has been historically associated with making a weld. In order for RFSSW to become a readily implementable welding solution, cycle times must be reduced to an acceptable level, similar to that of well developed, competing spot joining processes. In the present work, an investigation of the RFSSW process is conducted to evaluate factors that have traditionally prevented the process from achieving fast cycle times. Within this investigation, the relationship between cycle time and joint quality is explored, as is the meaning and measurement of cycle time in the RFSSW process. Claims and general sentiment found in prior literature are challenged regarding the potential for high-speed RFSSW joints to be made.

Due to the limitations on resistance spot welding of ultra-thin steel sheet (thicknesses below 0.5 mm) in high-volume automotive manufacturing, a comparison of friction stir spot welding and self-piercing riveting was performed to determine which process may be more amenable to enabling assembly of ultra-thin steel sheet. Statistical comparisons between mechanical properties of lap-shear tensile and T-peel were made in sheet thickness below 0.5 mm and for dissimilar thickness combinations. An evaluation of energy to fracture, fracture mechanisms, and joint consistency is presented.

As automotive designs add more aluminum to lightweight their vehicles, friction stir welding (FSW) will likely become a principal joining process in the industry. FSW is a solid-state joining process which avoids many of the traditional problems of welding aluminum alloys such as hot cracking, porosity and solidification shrinkage. These attributes enable high preforming friction stir welded joints of cast, 5XXX, 6XXX, 7XXX or mixed aluminum alloy combinations. Although FSW technologies have advanced to support high volume applications and have been applied in current automotive parts, its inability for nondestructive evaluation (NDE) increases the cost to manufacture friction stir welded parts. Current state of the art NDE methods for FSW are either ultrasound or radiographic technologies which add complexity to manufacturing lines and additional costs to FSW production. Many have researched ways to reduce NDE costs by using measured forces of the FSW process.