Experimental analysis of the flow drill screw driving process

Abstract

Flow drill screw (FDS) driving is a thermomechanical assembly process that allows for single-sided access multi-material joining, with a high application potential for modern lightweight vehicle design. The process combines three consecutive operations which partially overlap: flow drilling, thread forming, and tightening. The paper extensively investigates the process parameter effects on the flow drilling operation of thin sheet AA5182-O 2.5-mm thick and DP600 1.4-mm thick. Drilling defects have been associated with specific ranges of control parameters. Mechanical tests have shown that the drilling defects do not have a significant impact on the mechanical strength of the assembly under static loading. These results were used to determine both the optimal joining parameters and the robust process window. The variation of all process-relevant mechanical quantities was recorded over the whole available process window. This data may further serve for process simulation validation, or alternatively for the construction of data-driven meta-models.