Effect of Composite Scanning Strategy on Forming Quality, Microstructure, and Tensile Properties of Laser Powder Bed Fusion Titanium Alloy

Abstract

Laser powder bed fusion (LPBF) technology offers significant advantages in manufacturing complex-shaped titanium alloy components. Traditional scanning strategies, such as zigzag and island scanning, however, often fall short in fabricating parts with variable cross sections. To enhance the forming quality of components featuring combined thin-walled and bulk structures, a composite scanning strategy is proposed that adapts to the local characteristics of parts. This novel approach is designed to employ both island and zigzag scanning within the same deposition layer, aiming to optimize the balance between porosity and stress distribution. Notably, with a feature transition distance of 4 mm and a scan line offset of 0.67 mm, the specimens achieve a tensile strength of 1311.0 MPa, a yield strength of 1103.0 MPa, and an elongation of 8.8%. This strategy leads to the optimization of defects and a transition in microstructure for combined structural features. These promising outcomes lay the foundation for the intelligent allocation of scanning strategies and the high-quality formation of complex-shaped, high-strength titanium alloy parts.