Investigation of the effect of using an energy director on the quality of static ultrasonic welding of CF/PA۶ thermoplastic composite

Ultrasonic welding is one of the fastest methods for joining thermoplastic composites, resulting in high-strength connections. In this method, ultrasonic vibrations are transmitted to the composite material, generating viscoelastic heat within it, which provides the necessary energy to melt the polymer. By simultaneously applying pressure to the overlap of the welded samples, a high-strength joint is formed in a fraction of a second. In this research, various static ultrasonic welding tests, with and without an energy director, were conducted, considering three parameters: generator power percentage, welding time, and welding pressure. By analyzing welding energy consumption and the fracture surface, the effect of the energy director on the quality of static ultrasonic welding was determined. The results showed that welding shear strength is directly related to energy consumption. Low energy results in weak welds, while excessive energy causes polymer decomposition and thermal degradation of the composite. Using a ۰.۳ mm thick flat energy director made of PA۶ concentrates the viscoelastic heat at the interface, reducing energy consumption, preventing thermal degradation, and increasing the joint shear strength.

کلیدواژه ها:

Static ultrasonic welding ، Thermoplastic composites ، CF/PA۶ ، Joining