An Overview of Numerical Simulation of Heat and Mass Transfer in Wire Arc Additive Manufacturing

The wire arc additive manufacturing (WAAM) process involves the feeding and melting of wire, the transition of metal to a molten pool, the convection of liquid metal within the pool, and solidification. Defects may arise due to the complex, multi-physics nature of the process. Therefore, it is necessary to comprehend these physical phenomena through high-fidelity numerical simulations to establish a theoretical foundation for optimizing process conditions and producing high-quality products. This paper provides a comprehensive review of the key technologies involved in the numerical modeling of heat and mass transfer within WAAM and offers an outlook on potential future research directions. First, an overview of various heat source models is presented. Given that the formation and evolution of the molten pool in the WAAM is influenced by multiple driving forces, an analysis of buoyancy, electromagnetic force, surface tension, arc pressure, and arc shear stress is conducted. The impact of these models on fluid flow and surface deformation of the molten pool is evaluated. Subsequently, three metal transition models are summarized, including utilizing a velocity inlet filled with liquid metal, incorporating a spherical mass source term at a designated position, and establishing a solid metal welding wire directly. Finally, the commonly employed gas-liquid interface tracking method is introduced. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.