Analysis of a bimetallic joint produced by warm forging of an additive manufactured steel and rolled aluminum

Abstract

This study investigates the feasibility of a bimetallic joint between a low-alloy steel preform produced by Wire Arc Additive Manufacturing (WAAM) and a rolled AA6351 aluminum bar through the warm forging process. The combination of additive manufacturing and thermomechanical deformation aims to explore the synergy between the geometric flexibility of wire arc deposition and the mechanical properties enhanced by controlled plastic deformation. Joints were produced at average temperatures of 750°C, analyzing thermal deformation and observing the steel's behavior in prints at 0°, 45°, and 90° directions to analyze its anisotropy. Microstructural characterization evidenced the formation of an intermetallic bonding zone between the materials, where the joint was significantly influenced by the deformation and temperature of the metals. Tensile and hardness tests revealed that the joint integrity critically depends on the metallurgical adhesion at the interface. The results demonstrate that warm forging is a promising route for integrating steel-aluminum bimetallic components with potential applications in sectors such as automotive and aerospace, where combining lightweight design with mechanical strength is required.