Abstract: In our previous studies have found that transverse ultrasonic vibration technology can effectively improve the plasticity of titanium alloy materials. In order to further promote its application in riveting process, Ti-45Nb rivet connection of CFRP laminated as research object are compared and analyzed the connection domain performances by conventional riveting (CR) and transverse ultrasonic vibration-assisted riveting (TUVAR), and the influence mechanism from microscopic characteristics to mechanical properties is revealed. The researched results show that the shear band of the driven head became narrower under the TUVAR process, and the grains deformation is the largest in this region, the grain morphology of the rivet shaft hardly changed. However, the grain boundary angle, grain boundary number and texture orientation of the driven head and rivet shaft had significant changed. The micro-hardness of rivet driven head region 1 increased significantly due to the acoustic residual hardening effect. Comparing with CR’s specimens, the average maximum tensile load of TUVAR’s CFREP titanium riveted specimen is increased by about 4.35%; The relative deformation of the hole after 1×10⁶ fatigue loading of TUVAR specimens are reduced by 28.0% and 23.7% respectively Under cyclic stress levels of 40% F_ult and 50% F_ult, and the residual fatigue strength is increased by 5.3% and 3.2% respectively.

Key words: transverse ultrasonic vibration-assisted riveting, CFRP laminates, microstructure, mechanical property