Resistive Susceptor Design for Uniform Heating during Induction Bonding of Composites

Abstract

A novel susceptor concept for metal mesh susceptors, designed to achieve uniform in-plane temperatures during induction heating, is documented. The process involves redirecting eddy current flow patterns in the resistive mesh susceptor by specifically designed cut patterns in the mesh. A theoretical model was developed to predict heat generation in metal mesh susceptors with any prescribed network pattern. Initial results for meshes with cut patterns show significant changes in heating compared to an uncut mesh. Cut patterns can be optimized to reduce temperature gradients in the susceptor to within the processing window of the composite. Experimental results are presented for qualitative comparisons.

Fusion Bonding/Welding of Thermoplastic Composites

“…The key to successful bonding is to have a uniform temperature distribution in the bond area during the induction bonding. Uniform temperature distribution in the bond area depends highly on the design of coil and the implant configuration [52,53]. The uniformity of the magnetic field depends mainly on the coil design.…”

“…Yarlagadda et al [53] studied the effects of a metal mesh implant design on heating distribution during induction bonding of thermoplastic composites. By selective removal of segments from the uncut mesh, the resultant heating pattern and temperature distribution was made more uniform, resulting in better weld quality [53].…”

“…The coil is made of copper and must be water-cooled. In order to have an adequate polymer flow and consolidation, the implant typically contains some polymer, such as polymer-impregnated metal mesh, or an extra layer Fusion Bonding/Welding of Thermoplastic Composites of polymer [53]. The key to successful bonding is to have a uniform temperature distribution in the bond area during the induction bonding.…”

“…By selective removal of segments from the uncut mesh, the resultant heating pattern and temperature distribution was made more uniform, resulting in better weld quality [53]. Lin et al [54] developed a working induction heating model, which was capable of predicting relative heat generation pattern in graphite/thermoplastic composites.…”

Accelerated Adhesive Curing for Induction-Based Repair of Composites

“…These methods have traditionally been plagued by nonuniformity of heating in the plane of the bondline. Several techniques have recently been developed [3,4] that enable uniform heating of the susceptor in the plane of the bondline.…”