Flow Drilling for Joining Stronger Materials

Technical Summary:

FDS is a slow process compared to many other joining processes, and is limited by the 8Nm torque limit of the commonly used and lightweight M5 fastener. By applying electricity from the left to right ends of both sheets when two aluminum sheets are being joined, or from the bottom in an aluminum on steel stack, process time is reduced. Current is initially applied during the finding process, and ultimately leads to an 18% decrease in installation torque and a 32% reduction in process time due to a pre-process starting temperature of 128 °C. Not only does this process retain one-sided accessibility, but this addition of electricity allows the M5 fastener to penetrate a commonly used, stronger material such as Boron Steel, which it would otherwise fail to be able to.