Numerical Research on Cfrts-Tc4 Laser Stir Welding with Interfacial Micro-Texturing Pretreatment

Abstract

To investigate the influence of interfacial micro-textures on the performance of joints between carbon fiber reinforced thermosetting composites (CFRTS) and TC4 titanium alloy a finite element model of CFRTS-TC4 laser welding was established. The temperature distribution within the joint was simulated and observed using a high-speed infrared thermal imager. Despite a slight variation between the observed and simulated temperatures, both results exhibited a consistent change trend. Specifically, the study focused on the temperature profiles at various locations, including the top surface of the TC4 alloy, the joint interface, and the CFRTS surface. A comparative analysis was then conducted to assess the temperature distribution in joints with and without micro-texturing. The findings indicated that joints with micro-texturing had a lower temperature peak compared to those without, while exhibiting a similar temperature trend. This temperature variation was attributed to the alteration of the contact surfaces resulting from laser micro-texturing, shifting from a single-plane surface to a grid formation. The grid structure increased contact with air, thereby improving heat transfer and allowing the PA6 resin to effectively fill the gaps between the carbon fibers and the CFRTS material. Consequently, the reduction of thermal defects and the enhancement of joining strength were achieved through this approach.

Keywords: Laser welding, CFRTS-TC4 joint, Laser micro-texture pretreatment, Numerical simulation