Thermoplastic welding is an emerging technology targeted at significantly reducing the manufacture of aerospace structure by eliminating fasteners and the touch labor associated with fasteners to prepare, install, and inspect the assemblies. Thermoplastic welds, however, suffer from low pulloff strength because the metal foil susceptor used to heat the bondline is essentially a foreign substance in the weld that is unreinforced. The susceptor of the present invention provides Z-direction barbs on the susceptor to increase the pulloff strength.