Friction Riveting of glass-fibre-reinforced polyetherimide composite and titanium grade 2 hybrid joints

Abstract

In this work, the feasibility of Friction Riveting on thermoplastic composite laminates with metals was investigated on glass–fibre-reinforced polyetherimide with titanium grade 2. Microscopy analysis (light optical and laser scanning confocal microscopy), temperature monitoring (infrared thermometry) and quasi-static mechanical testing (T-pull tensile testing) were used to investigate joint properties. Joints with reduced amounts of thermo-mechanically modified composite material with moderate to high tensile strengths (1.9–4.0 kN) were achieved. The average process temperatures (430–464 °C) of the molten matrix were below the range inducing the extensive thermal degradation of the polyetherimide matrix and out of the range inducing the plasticising of titanium grade 2. The Volumetric Ratio, a simplified analytical model describing the anchoring efficiency of the rivet, was demonstrated to be directly proportional to the tensile strength of the joint and therefore an adequate analytical model to describe the mechanical performance of joints. Finally, a correlation between the rotational speed, heat input, process temperature and rivet plasticising was observed. The higher the rotational speed was, the higher the heat input, temperature and deformation of the plasticised rivet tip became, leading to higher rivet anchoring performances.