Microstructure and Property Optimization Mechanisms of TiC/Al-Cu Alloys Prepared by Ultrasonic Frequency Pulsed Wire Arc Additive Manufacturing

Abstract:

To address the issues of TiC particle agglomeration and pore defects of TiC particle-reinforced Al-Cu alloys prepared by wire arc additive manufacturing (WAAM), this study proposed a novel ultrasonic-frequency pulse (UFP)-assisted WAAM process. By modulating arc thermal characteristics, this method enhanced convective and turbulent behaviors in the melt pool, transitioning from a conventional Marangoni-driven flow to a more uniform dual-vortex structure. A computational fluid dynamics model was developed to trace TiC particle motion and revealed their improved mixing mechanism with the matrix under UFP conditions. Simulation results were validated by real-time melt pool imaging. Results showed that compared to conventional VPTIG, the UFP-VPTIG technique can significantly refine grains and improve homogeneity. Dispersed TiC particles are more uniformly, and porosity and segregation defects are reduced. This study offers a promising route for manufacturing high-performance Al-Cu alloy components.