Novel Heating Elements for Induction Welding of Carbon Fiber/Polyphenylene Sulfide Thermoplastic Composites

Abstract

Conductive films of carbon nanofibers (CNFs) decorated/coated with metals, either silver (Ag) or nickel (Ni) are fabricated using a solution casting process and used as novel heating elements (HEs) for induction welding of carbon fiber/ polyphenylene sulfide (CF/PPS) thermoplastic composites. Prior to making the films, the metal-coated CNFs are prepared by an electroless plating method using Ag or Ni precursors. A solution of the metal-coated CNFs is then casted onto a pure PPS film to give a robust conductive film upon solvent evaporation and annealing in an oven at 200 C. SEM observation and electrical resistivity measurements reveal that the CNFs are successfully coated with the metals which result in a significant decrease of the films' electrical resistivity. A third type of HE is also fabricated by solution mixing Ag-coated CNFs and magnetic Fe 3 O 4 nanoparticles. The welding efficiency of the fabricated films is assessed for induction welding of two different types of thermoplastic composites, that is, unidirectional pre-impregnated 16 plies of CF/PPS compression-molded in a quasi-isotropic stacking sequence and 8-ply of satin weave fabric CF/PPS compression-molded in a cross-ply stacking sequence. The mechanical apparent lap shear strength (LSS) of the induction-welded joints is evaluated for the fabricated HEs and compared with the LSS of joints welded using conventional stainless steel mesh susceptors. Under similar testing conditions, Ag-coated CNFs HEs lead to the highest LSS with an average value of %31.5 MPa. In general, the new HEs result in superior LSS and higher heating rates when compared to the metallic mesh counterparts. The present work offers a new perspective to push the boundaries toward high quality welding of thermoplastic composites using nanomaterials-based HEs. Fig. 7. Representative optical micrographs of the welded sample cross-section (a-c) and fractured top-view area after lap shear tensile testing (d, e) for the SWF CF/PPS composite adherends welded using (a and d) HE#1-serie3, (b and e) HE#2, and (c and f) HE#3.

Disassembly Study of Ultrasonically Welded Thermoplastic Composite Joints via Resistance Heating

“…In the literature, a wider range of studies on nanocomposite films as susceptors for the induction welding of TPCs or induction heating of adhesives have been carried out. Farahani et al showed that silver nanoparticle-based thermoplastic films are suitable as susceptors for induction welding, reaching melting temperature in less than 50 s at 400 A [ 40 , 41 ]. However, the potential for disassembly and the repair of fusion bonded TPC joints has not been investigated in the literature.…”

A Study of Films Incorporating Magnetite Nanoparticles as Susceptors for Induction Welding of Carbon Fiber Reinforced Thermoplastic

“…Thermoplastics are superior in toughness and environmental resistance and are superior to most thermosetting resins in terms of their short processing time, incombustibility, and long lifecycle. Additionally, thermoplastics can be produced quickly at low cost [1][2][3][4].…”

Inductive Heating Using a High-Magnetic-Field Pulse to Initiate Chemical Reactions to Generate Composite Materials

“…Induction heating (IH) is used in industry, medicine, household, et cetera [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40]. As non-ionizing radiation it is applied to trigger or to control physical processes and chemical reactions (see Figure 1).…”

“…The overall heating properties of particulate embedded susceptors are difficult to predict because these various factors, (a) to (d), are related to each other by complex behavior [2]. A poor adhesion with the surrounding polymer can create defects within the polymer and lead to residual stress at the interfaces and, probably, excessive deformation [32].…”