Ultrasonic welding (USW) provides a cost-efficient method for joining fiber reinforced thermoplastic composite (FRTP) which is increasingly used in various industries as a kind of emerging lightweight material. As a result of the distinct 3D fibrous and porous network structures of FRTP together with the ultrafast and multiphysical features of USW, a great deal of interest has been generated to study the fundamentals and applications of this novel joining technique. This paper presents the current understanding of the USW of FRTP, focusing on the weldability, welding quality, and underlying mechanisms in acoustic transmission, heat generation and joint formation. Then, the challenges to understanding this technique are addressed such as the special physical properties due to fibrous fillers, interphase interaction under ultrasonic energy, and melting and molecular inter-diffusion at the interface. This work contributes to the optimal parameter selection in the USW of FRTP and thereby the wide applications of FRTP.

超声波焊接 (USW) 为连接纤维增强热塑性复合材料 (FRTP) 提供了一种经济高效的方法，FRTP 作为一种新兴的轻质材料越来越多地用于各个行业。由于 FRTP 独特的 3D 纤维和多孔网络结构以及 USW 的超快和多物理特性，人们对研究这种新型连接技术的基础和应用产生了极大的兴趣。本文介绍了当前对 FRTP 的 USW 的理解，重点介绍了可焊性、焊接质量以及声传输、发热和接头形成的潜在机制。然后，解决了理解该技术的挑战，例如由于纤维填料的特殊物理性质、超声波能量下的相间相互作用、以及界面处的熔化和分子相互扩散。这项工作有助于在 FRTP 的 USW 中选择最佳参数，从而促进 FRTP 的广泛应用。