Computational Fluid Dynamics Simulation for Additive Friction Stir Deposition of Aluminum Alloy

Abstract

Additive friction stir deposition (AFSD) is a novel additive manufacturing (AM) technology in which solid-state, friction-stirred metal is deposited layer-by-layer to build three-dimensional parts. Unlike the mainstream fusion-based AM methods, AFSD does not cause metal melting and solidification. Therefore, AFSD can eliminate defects such as lack-of-fusion, key-holing, and large residual stress. Currently, the understanding of AFSD is based on the friction stir welding (FSW) process that has been widely studied for the past two decades. However, the material feeding and spreading in AFSD is essentially different from FSW and can complicate the thermal field and material flow. In this work, a computational fluid dynamics (CFD) model is created to simulate the temperature and fluid flow for AFSD of aluminum 7050 alloys. The predicted temperature is validated against both literature and thermocouple measurements. The current work lays the foundation for a quantitative understanding of AFSD process physics and the simulation-guided process design to tailor the thermal-mechanical field.