3D Finite element modeling and experimental investigation of micro milling of laser powder bed fusion fabricated Ti6Al4V

Abstract

Laser powder bed fusion (LPBF)-manufactured titanium alloy (Ti6Al4V) has become a preferred material for micro-components in various industries due to its superior mechanical properties compared to conventionally produced wrought alloys. Finite element (FE) simulations provide an efficient and powerful method for modeling complex machining processes, minimizing the need for extensive physical experiments while saving time and resources. However, existing FE models oversimplify high-speed micro-milling as overlooking critical aspects especially tool rotation and the interactions between the cutting tool and workpiece surfaces. This leads to inaccurate predictions of chip formation and surface quality. This study introduces an advanced 3D finite element model (FEM) for micro-milling that incorporates orthogonal cutting constraints, tool rotation, and the intricate interactions between the cutting tool and workpiece for LPBF Ti6Al4V. The model effectively captures the shearing process and simulates cutting forces, chip morphology, and surface topologies under various machining conditions. Experimental validations confirm the model's reliability and robustness, demonstrating strong agreement with simulation results. The model also adapts well to variations in machining parameters. Key findings reveal that increasing the depth of cut raises cutting forces due to enhanced material removal, while higher tool rotational speeds at a constant depth of cut increase cutting forces because of elevated friction. These parameters significantly influence chips profiles, surface defects and overall quality. This validated 3D FEM offers critical insights for optimizing the micro-milling of LPBF Ti6Al4V components, providing a reliable tool for advancing precision manufacturing strategies.