Systematic investigation into laser powder bed fusion of Ti-5553 through single-track and multi-layer studies for tailored manufacturing solutions

Abstract

Laser Powder Bed Fusion (LPBF) is recognized as an appealing fabrication process for producing metallic parts with customized properties. In the current research, a comprehensive approach is employed to systematically correlate single-track and multi-layer fabrication, aiming to generate a reliable process map, assess the effect of process parameters on the properties of LPBF-made Ti-5553, and guide the manufacturing of tailored structures. Based on single-track morphology, melt pool geometry, and multi-layer density, 30 combinations of laser power and scanning speed were categorized into three groups to identify the desirable process parameters. The investigation of single-tracks and multi-layers reveals that deeper melt pools, created with higher energy input, result in a more elongated grain structure, higher α phase content, increased strength and hardness, and reduced ductility. It is observed that achieving higher ductility involves a slight decrease in strength. Specifically, a substantial increase of ∼65% in ductility occurs with only a ∼3.5% reduction in strength. Also, it is found that the volumetric energy density (VED) alone is not sufficient as a design parameter, and the significant process parameters (e.g., laser power and scanning speed) should be considered, as two samples with the same VED yield different properties.

Keywords

• Additive manufacturing
• Laser powder bed fusion
• Process optimizing
• Single-track
• Microstructure
• Titanium alloy