Development of novel wire-based steel bridges using a coaxial laser bonding process

A novel coaxial laser wire bonding process has been developed for the manufacture of wire-based steel bridges. The wire bridges, which have the capacity to absorb tensile forces, enable the manufacture of weight-optimized components. The process is initiated with the establishment of a starting point by means of laser wire bonding, followed by the arc-shaped drawing of the wire, and concluded with the setting of an end point using the bonding process. The effects of varying combinations of focus position and laser power on the stability of the wire bridge process were investigated by bonding G4Si1 (ER70S-6) steel wires with a diameter of 1.0 mm to a mild steel substrate S235JR (AISI 1015). A specific movement profile for the laser processing head with variable geometric parameters has been developed based on the bridge length and the bridge symmetry. Furthermore, the geometric limits of the bridge were determined using the aspect ratio of the bridge height to bridge length. The symmetrical and asymmetrical bridge shapes were examined, and the influence of the bonding and geometric parameters on the maximum tensile force of the wire bridge was evaluated. Through the optimization of these parameters, a maximum tensile force of 909 N was successfully attained for a steel wire bridge exhibiting an asymmetrical structure.