Resistance Welding of Graphite Polyetheretherketone Composites: An Experimental Investigation

Resistance welding of preconsolidated unidirectional graphite (AS4) rein forced polyetheretherketone (PEEK) composite laminates (I.C.I. APC-2) is investigated experimentally. An apparatus is developed to conduct experiments to identify important process variables governing the efficiency of the welding process. Experiments were con ducted under displacement control and prescribed initial consolidation pressure. Heating elements consisted of a single ply of APC-2 with adjacent layers of neat film to minimize current leakage into the laminates to be welded. Temperature at the weld interface and consolidation pressure versus time were monitored and provided insight into the welding process. A strong correlation between the extent of welded surface area and process parameters such as power, energy and time in the melt were demonstrated. The quality and extent of the welded surface is quantified using ultrasonic nondestructive evaluation techniques. Experimental results indicate that superior welds exhibiting greater repro ducibility are obtained at lower power levels that promote more homogeneous temperature distributions.