Process and Performance Evaluation of Ultrasonic, Induction and Resistance Welding of Advanced Thermoplastic Composites

The possibility of assembling through welding is one of the major features of thermoplastic composites and it positively contributes to their cost-effectiveness in manufacturing. This paper presents a comparative evaluation of ultrasonic, induction and resistance welding of individual CF/PPS thermoplastic composite samples that comprises an analysis of the static and dynamic mechanical behaviour of the joints as well as of the main process variables. The induction welding process as used in this research benefited from the conductive nature of the reinforcing fibres. Hence no susceptor was placed at the welding interface. Resistance welding used a fine woven stainless-steel mesh as the heating element and low welding pressures and times were applied to prevent current leakage. Triangular energy directors moulded on a separate tape of PPS resin were used to concentrate ultrasonic heat at the welding interface. The static single lap shear strength of the joints was found similar for induction and ultrasonic welding. A 15% drop in the static mechanical properties of the resistance