Resistance welding of thermoplastics by carbon nanotube-grafted heating element
Xuhai Xiong, Daosheng Wang, Jian Wei, Pu Zhao, Rong Ren, Jiapeng Dong, Lin Tian, Wei Wang, Xu Cui
Abstract
The surface of stainless-steel (SS) mesh was modified by growing carbon nanotubes (CNTs) from ethanol flame. The CNT-modified SS mesh was then used as a heating element for the resistance welding of glass-fibre-reinforced polyetherimide (GF/PEI) laminates to improve the interfacial bond strength of SS wire and PEI resin. Interfacial microstructure, the mechanical properties of the welded joint and the effects of CNT growth time (tg) on the wettability of PEI resin solution to SS wire were investigated. The results indicate that the addition of CNTs increased wettability due to the capillary action of high-porosity CNT coating. The microstructure of the welded joints changed with tg, and the thickness of the welding implant layer decreased below tg = 10 min, and the maximum single lap shear strength (SLSS) value of the welded joint was 39.2 MPa when tg = 10 min. The strengthening mechanism of CNTs and the failure modes of the welded joints were also elucidated in detail by the interfacial shear strength (IFSS) between SS wire, PEI resin and the fractography analysis.